So, I have a wiki category and I'd like to restrict creating threads to admins but allow regular users to edit the OP -- I set it up like that and thought it was fine.
Then I noticed one of the wiki threads was moved to a different category. First, I think regular users editing wiki posts created by others shouldn't be able to edit the category/title. And second, that user didn't even intend to move the thread -- because he didn't have access to create threads in that category, the category dropdown defaulted to the general category and didn't let him reselect the wiki category.
I guess a workaround would be to make the second post in the thread the wiki post, but that seems icky.