Regarding his mask: Well, I think my thoughts on what should happen are clear enough.

Though burlap sacks are a dime a dozen, "Stage Two" would have a much more terrifying effect on the victim, and would look far better with a suit, IMHO.
(And yes, I realize that the main reason "Stage Two" wasn't used for
BB was because Nolan was afraid it would cause the rating to jump up to R. But after seeing the Joker's look, the darker feel we're supposed to have in
TDK, and the sides I've seen, using "Stage Two" seems like a natural progression.)