I don't think I've ever not allowed that sort of thing, but considering the ever increasing amount of trolls going anon and pervs using private opinions, I might start not allowing it, depending on the question or take.
Yes. I only get gender specific for certain questions when I want constructive responses and not the usual GaG banter. It doesn't stop the diehard critics from jumping on their opposite gender accounts to share their unwanted two cents though.
The problem I have is answering them... I don't know who they are so I assume they aren't the ass-hats that I've gotten in to arguments with. A couple times I've had a few badger the hell out of me with dozens of questions. I got tired of repeating myself that I ignored the "notifications" and they started insulting me. I even told the one 25-29 guy that.. his attitude was the reason """ I """ was the only one answering his question... and it was him and not me that had the problem.