Re: Which villain(s) should the reboot start with?
Mr. Freeze seems a good choice to me. He's not a rehash of anything (other than the godawful B&R movie) and has an intriguing backstory. It's also fanciful enough to differentiate the movie from Nolan's, but could be done in a grounded enough way to still be in a serious comic movie.
Plus, it challenges Batman's notions of black and white good guy/bad guy that the movies have gone for thus far (Other than Dent and maybe...maybe Ra's).
Riddler could be fun, but might be too Joker-like. Unless he is a co-villain. Black Mask could be interesting, but Mad Hatter seems too ridiculous and too much like Scarecrow.