Phew, this was a really long request. It took a long time to work through all of this, but I'm going to try. As you've mentioned a lot of this has been documented in multiple places - MSE, MSO, help center, etc. While I'm going to go over most of this, I will also be linking to many of the canonical posts where this is already outlined because there no sense it putting things in more places to potentially become obsolete.
A question can take various paths on a site. I think I've tracked down all the places and ways a question can move, how it gets there, and what can happen to it once it's there.
Here is a flowchart with most of it documented, all the verbiage on how it moves is below:
What happens on question submit?
When a question is first posted it can initially take a few paths:
- If it's a first question by a user, then it will automatically head into the First Posts Review Queue.
- The question is also checked against some heuristics to get its quality score. Depending on that score, it may go into Triage on Stack Overflow or into the Low Quality Review Queue elsewhere on the network.
- If it's not a first post or the quality score is high enough, then the question will head to the homepage.
Note: A newly posted question can appear in multiple places at the same time. It can be going through the review process in the First Posts Review Queue and be shown the home page simultaneously.
What happens with question edits?
After the question is posted it potentially could be edited. Edits are applied in a variety of ways:
- Immediately
- by the OP, who can apply edits to their own post, they can also unilaterally review a suggested edit by others
- by users with edit privileges (> 2k rep)
- by diamond moderators
- Users without edit privileges (< 2k rep) will suggest an edit, sending the question into the suggested edit review queue. At that time, the OP can review the edit or it would have to wait for review to handle it.
- If an edit is proposed by an anonymous or unregistered user, it immediately goes to the suggested edit review queue for handling.
In order for the edit to be applied from the Suggested Edit Review Queue, the community must reach a consensus on it, unless it is unilaterally accepted or rejected by the OP or a moderator.
What happens when a question gets flags or close votes?
Any time after a question has been posted, users with > 15 rep have earned the privilege to flag a question for a variety of reasons. Depending on the type of the flag that is raised, different things will happen to the question
- Spam flags - if a question accumulates 3 spam flags it is automatically removed from the homepage. 6 spam flags result in the question being locked and deleted, and the OP receives a reputation penalty of -100 for posting the spam. Posts that have been flagged as spam bubble to the top of the moderator flag queue for handling, as they are considered high priority
- Rude or abusive flags are handled behind the scenes exactly the same as spam flags. 3 flags will hide the question, 6 flags to lock and delete it.
- Raising a 'in need of moderator attention' flag sends it to the mod flag queue for handling.
- If a question has a score of <= 0, it's less than 7 days old, and it's not currently in review (Triage or Close), then a user will be presented with an option to flag it as 'very low quality'. This flag will send the questions into Triage on Stack Overflow or the Low Quality Review queue elsewhere. This flag will, however, only send the question to the queue once. If it's raised again, it will go to the moderators to handle.
- The remaining flag options on the dialog are for closing a question. Any one of these flags will send the post into the Close Vote Review queue for handling.
- If a user with close vote privileges uses the flag dialog to flag to close a question, the system automatically knows these are close votes not flags - a user would technically be voting to close not flagging to close.
- Flags to close a question are declined, if the question goes to review and the community votes to leave the question open. If the post has a flag to close question on it, and the question is edited in review, then the flag is marked helpful.
Closing a question requires 5 votes to close, unless it falls into one of these categories:
- A moderator can single-handedly close a question
- A gold badge tag holder can hammer a question that they believe is a duplicate.
- The OP can auto-close their question, if it has received duplicate votes or flags.
Once a post is closed, the displayed reason for the closure is based on a few rules outlined on Meta Stack Exchange and Meta Stack Overflow, but here is a quick overview:
- If it is a top level reason (duplicate, too broad, unclear what you're asking, or primarily opinion-based), then the one with the most close votes is shown. In the event of a tie, the most recent vote is displayed.
- For specific off-topic close reasons - any reason that gets at least 2 votes is shown which does allows more than one to be displayed. That is unless it's a custom off-topic reason, as these aren't shown in the box and are posted as a separate comment.
Close votes for unclear what you're asking, too broad, or primarily opinion-based simply help close a question. The same behavior applies to the some site specific off-topic because… reasons that exist.
Every site has an off-topic...belongs on another site (migration) option. The list of available target sites is limited to 5 total: one for the child meta, and four for other sites. The remaining slots are filled as needed and typically are filled only for graduated sites.
Questions can be migrated to another site either single handedly by a moderator, or by votes from the community - if migration paths have been set up. Migration targets are only available for 60 days. When a question is migrated to another site, the post on the originating site is closed/locked, and it is sent to the target site. Users with > 10k reputation are able to see a list of questions migrated both to and away from a site (/tools?tab=migrated), along with statistics about rejections.
Moderators do have the ability to migrate to sites not listed in the preset list of targets, however the general rule of thumb is to not migrate crap. If a question is borderline when it comes to quality, most of the time the moderator will not migrate it to another site and will simply close it as off-topic.
When a question does receive its first close vote, it will automatically go into the close review queue. Questions are somewhat sorted in review - it is based on how recently an item hit the queue as well as the number of previous reviews on the post...the more prior reviews, the closer to the front of review it appears.
A few extras about closed questions:
- They can still be flagged by users - if it's spam, rude or abusive, or in need of moderator attention.
- Closed posts can be reopened, undoing the closure - with a single vote by moderators or by users with reopen votes.
- If a closed question gets an edit within five days, or a reopen vote at any time, then it will go into the Reopen Review Queue for community handling.
How do questions get deleted?
Questions either closed or not, can be deleted multiple ways:
- As with most other things, moderators can unilaterally delete a question with a single vote.
- The OP has the ability to self-delete a question, unless it has an upvoted or accepted answer, or multiple answers.
- The system will also automatically delete questions as part of the Roomba process. All the rules involved in Roomba/Community deletions are outlines in the help center and in the FAQs.
Questions that are already closed can accumulate delete votes from users who have earned the privilege (> 10k rep). It takes 3 delete votes to delete most questions. The number of delete votes changes if the question is considered a popular one, then it has additional rules, but will never need more than 10 votes. Once a question gets its first delete vote, it appears in the 10k tools list along with the number of votes it has accumulated.
Questions that have been deleted can be undeleted by a moderator, or by the OP if they deleted the question. These questions also appear in the 10k tools (/tools), where users can review a list of both recently deleted and recently undeleted posts, as well as posts accumulating undelete votes.
What happens to a question in review?
At any time, if a moderator reviews a question in review, the action they take is binding and the post is dequeued immediately.
###Close Review Queue As soon as a question gets a close vote or a recommend closure flag, the post is sent to the queue. As mentioned above, the questions are somewhat sorted in review. Users can select from 4 actions:
- Leave Open votes to leave the question open and if the post receives 3 of these, then the question is dequeued from review
- Close adds another vote to close the question. If it's the 5th vote, then the question is closed and dequeued.
- Edit - if selected by a user, they will edit the post and once the edit is applied, the question is removed from review.
- Skip just bypasses the current question and moves to the next.
Low Quality Review Queue
For questions, this queue applies to all sites except for Stack Overflow. On SO, the LQ review queue only contains answers. It gets fed by heuristic score as well as VLQ flags on the SE network. When reviewing questions there are 5 options presented to users:
- Looks OK means there is nothing wrong with the question. This option will only dequeue the question if it has gotten enough Looks OK reviews. The number required is variable based on the number of flags on the question plus a number set by the site. For instance, if a site ordinarily requires a single Looks OK vote, but the question has 3 flags, then it would need to have 4 Looks OK reviews to dequeue it.
- Edit if the post can be fixed by an edit, user will dequeue the question once the edit is applied.
- Close this is a vote to close the question because it is not a good, on-topic question, but can be edited to be on-topic. If the vote is the fifth, then the post is removed from review.
- Recommend Close - this is shown in lieu of Close to users who don't have enough reputation to vote to close, or have run out of close votes. This option pushes the question into the Close Votes review queue and prioritizes the LQ review task for users who do have enough reputation and votes.
- Delete - this casts a delete vote on the question (if you have enough reputation and votes). This option is for questions that can't be improved if closed and should just be deleted.
- Recommend Deletion - this is shown instead of Delete to users without enough reputation to vote to delete, or have run out of votes. This causes the post to be prioritized for users who do have enough reputation and votes.
- If the question reaches enough delete votes cast inside and outside the review UI (3-9 depending on score), it will be dequeued. It can also be dequeued if six Recommend Deletion or Delete reviews (four on Stack Overflow) are cast. Note that in the latter case, if the question has a positive score, it will be forwarded to moderators instead of being deleted.
- Skip just moves the user to the next post in the queue.
Triage Review Queue
The Triage queue is only available on Stack Overflow. This is similar to the Low Quality queue on other sites with the goal being to quickly assess questions. Questions are fed into Triage via heuristics and by the VLQ flag.
The queue require 3 reviews of the same result on a question for it to be dequeued. There are four options for users to select in this queue, each one explained in detail on Meta Stack Overflow. Based on the result of the review, the question will move elsewhere on the site.
- Looks OK result will dispute any "very low quality" flags on the post and sends it to the homepage, no longer in review.
- Requires Editing pushes the question to the Help & Improvement review queue (see below).
- Unsalvageable option requires users to select any flagging action, such as spam, close vote, moderator intervention. Any of these will send the question to the Close Vote Queue or the moderator flag queue.
Help & Improvement Review Queue
This queue is only available on Stack Overflow and it is specifically fed by questions exiting the Triage queue when the result is that the post requires editing. There are only three options in this queue - edit, flag as "very low quality", or skip. An edit to the post will remove it from review immediately and send it to the home page. The "very low quality" flag would send it back into Triage. The movement of questions to and from the Help & Improvement queue is outlined on Meta Stack Overflow.
Suggested Edit Review Queue
Questions appear in this queue when it receives a suggested edit by a user without editing privileges, or an anonymous/unregistered user. The community must reach a consensus on edits suggested, or the OP or a moderator can accept or reject an edit unilaterally. There are five options in this queue: Approve, Reject, Improve Edit, Reject & Edit, and Skip. As usual, the skip button will simply advance to the next review. To dequeue a post from this queue, it must have either:
- a consensus of two users both voting to approve or reject
- a single user clicking "Improve Edit" or "Reject & Edit" and submitting an alternative form of the edit
- the question author or a moderator making any review (their vote is binding)
First Post Queue
This queue is populated by posts by new users less than 30 days old. A single review will remove this from the queue. Users can vote, edit, comment, flag, vote to close, etc on the question.
Reopen Review Queue
When a closed question gets an edit or a reopen vote (full details here), it gets bumped into this queue for handling. Once in the queue, if the question gets 3 Leave Closed votes, then it is dequeued. An 'Edit and Reopen' or 'Reopen' selected will add another vote to reopen, and if the it is the 5th vote, then the post will be removed from the queue.
Questions can hit review queues multiple times, based on votes, edits, etc. All of this has been outlined on Meta Stack Exchange.
I think I covered most, if not all of what you asked, but I also have no doubt that I've missed things and you will point them out. A question can move around a lot on the site - in and out of review queues. It is possible that some of these rules change over time, due to them being site settings that can be tweaked as needed, but overall this is the path that a question can take on a site.