Re: In hindsight what changes would you do
I think TDKR needed more female characters in general and more focus on "family" in particular. Also, a few more references to "Bat Mythos" couldn't hurt.
1. Replace Foley with Sarah Essen. She and Gordon have belligerent tension throughout the movie, she pulls him into her apartment to avoid a patrol, and at the end of the movie she shows Gordon a positive pregnancy test on the roof of Gotham Police HQ.
2. John Blake replaced by Ellen Yin, an Asian-American female police officer. She claims to recognize Batman is Bruce Wayne based on body language. At the end of the movie, we find out her legal name is "Cassandra."
3. Carmine Falcone, now sane (or saner) since BB appears in Blackgate Prison protecting Selena before the breakout. We're not sure why until Selena calls Carmine "Daddy," and not sarcastically. This is a callback to DARK VICTORY and WHEN IN ROME.
4. Lucius Fox has two female assistants, Francine Langstrom (sonar expert) and Nora Fries (freezing technology). They get Bruce back into Gotham and prevent the ice from breaking when Batman rescues Gordon. Lucius trusts them since he introduced them to their husbands, Kirk and Victor.
5. More bomb info, so we understand Gotham isn't rendered radioactive when it goes off.
6. Talia is killed by a sniper who gets away... and is revealed to be Jen, who is working for an unseen "Uncle Oswald." Not really a sequel hook, just that Gotham will be Gotham.
7. Barsaad lives! He is seen clean-shaven in a three piece suit, talking to "Mr. Cobblepott" over the phone. Again, not really a sequel hook. It shows how some people can even get the League of Assassins to do their bidding.