My answer to this question was accepted. However I don't believe the question itself will be useful to others in its current state. Is it appropriate to edit a question to be more meaningful to others after the answer has been accepted?
Edits can always be reverted. If it's obvious you're doing it with good intentions, I see no problems with it.
I recently edited a question title with an accepted answer. Here's my example.
I edited the title from something referencing blender plug-ins to something more generic.
Absolutely. A more general answer is better than a narrower one most of the time. If you need to edit the question to correspondingly be a little more generalized, so be it.
Hijacking a question to fit a pre-fabricated answer is what would be beyond the pale.
Another point: Not such a way that, The Accepted answer becomes invalid. It will be harmful for the site