A simple idea. How about a Stack Exchange site to serve as a buffer for questions that don't meet expectations in terms of quality ? A post could be temporarily migrated with a tag representing the originating site, the owner could be invited to improve their question along with some help and this could lead to overall improvement of the content on all SE sites.
What is meta?
- Any Stack Exchange user can ask a question
- The community provides support, votes on ideas, and reports bugs
- Your voice helps shape the way Stack Exchange operates
We already have a feature for that. It's called "closing"
When a post is closed, it is meant to be edited and improved if possible. Once that is done, it can get reopened. (You can flag it for reopening if you want)
When a post seems salvageable via edits, usually a community member will keep that in a comment. (This doesn't always happen on SO, I guess that ought to be fixed somehow)