Re: Batman should die in the next film!
It wouldn't merely be to be "edgy and different". If that was the only reason then I'd consider that to be a poor excuse to do that. It would be to bookend Nolan/Bale's run and open the door wide open for a new take on the franchise. Hopefully one that would enable Batman to fit in more with stuff like the other DC heroes or employ more of his more fantastical villains.
You know, it occurs to me that Captain America is basically the superhero equivalent of Mary Poppins. Practically perfect in every way and all that stuff.