Questions 3,4, and 5 have no way for someone who isn't very interested to say "I don't care, do what you like."
Basically, I'm fine with someone else giving it a try if they want to do it, and I won't feel that you are "destroying the show" if you do because the show exists as it is and isn't going to be changed by a few AU stories. But my gut feeling is that it would mess up most of the dynamics and characterization of the show so much that reading it wouldn't interest me, and I wouldn't want to write it. I'm also a little worried that it might suck people away from more interesting work, but that's up to them, not me.