Revealing mistake: When Blake and Gordon watch Bane on TV during Gotham's siege, a grey (sometimes white) square is reflected on Gordon's glasses. It's either a lighting screen or the proof that the TV is turned off and the image on it is added on post-production.
Revealing mistake: During the party, the second time Gordon gives a speech praising Dent, a lighting screen is reflected on his glasses, which disappears in opposite shots.
Revealing mistake: When Bane first breaks into the stock exchange, he forces one of the guards into shooting his gun. Two mistakes: there is no flash or muzzle flare, and the gun has an insane amount of recoil. It's not a cannon, it's a 9mm. It's also not the guard being startled by Bane: Bane is the one holding his arm.
Answer: He wanted to start a new life, which means shedding all aspects of his old one. Bruce Wayne was still a person of interest in the Gotham Wall Street scandal, with his death, his will would provide for and aid all the people affected by it.