What are my options if people don't understand my question, vote to close it, or answer 2000 miles away from it (while voting down of course)?
Should I open a new one, or can I ask a moderator to reopen it?
The FAQ didn't help.
I have edited your question and tried to clarify that it was different from the one it was closed as a duplicate of, and then somebody else edited it from there. I have also voted to close. You may roll back my edits or their edits if you like, or you may edit further from here to clarify.
This is what you need to do if you feel your question was closed in error; just edit your question to make it clear why it should be reopened. If it doesn't get reopened or you need help editing, ask here on MSO as you did.
If the question is not getting the answers you want, and it is getting closed as duplicate, I would rather let it get closed, and ask a new question making clear it is not a duplicate the other question, which means using a different wording.
This is what I would do especially in the case there are, for example, 4 up-voted answers. If you change the question after it has been answered, and those answers get up-votes, future readers will not understand if those answers are appropriate for the question being asked. It is probable that who answered the question doesn't notice it got changed, and the answers that are irrelevant would stay. You can flag them for moderation attention, but I am not sure what moderators would do in that case.
To me, it seems easier to start with a fresh new question, being sure to use a completely different wording.