Word on 1 & 3. That's the reason why I silently go "nonono" when someone mentions how cool it would be if X turned out to be evil in book 7. Rowling's villains are mostly effective and occasionally interesting, but they do NOT come with a sophisticated wardrobe, funny lines and extra sex appeal. It just isn't that kind of 'verse. Writing fic about, say, evil McGonagall might be entertaining - would she actually turn out to be bad it would only be depressing.