Re: The Joker sized elephant in the room
If Ledger were still alive, I could see Joker serving as the judge, just because he targeted Dent in TDK and because one of his stories about his past involved his wife getting involved with the mob. The scene could've elaborated more on Joker's past through the sentences he passed on the upperclass rich--businessmen and elected officials who were tied with the mob--and progressed Bane's plan for Gotham.
"I never asked for this crown. Gold is cold and heavy on the head, but so long as I am the king, I have a duty … If I must sacrifice one child to the flames to save a million from the dark … Sacrifice … is never easy, Davos. Or it is no true sacrifice." - Stannis Baratheon