So, I got two suggestions that may be useful, and may already be suggested, but I'm sure they are not.
- On your profile, you have a page called "Hidden Questions" that have all your hidden questions that are not deleted. Only your favorites users and editors and above can view them. Not sure if this is good. :P
- Have a notice saying if the question has been answered when typing an answer, or if you didn't refresh the page. Again, not sure if suggested or a horrible idea.
Well, those are my hopefully helpful suggestions.