Re: In hindsight what changes would you do
Realistically, batman ends up in jail after the central intelligence get a hold of his paper work as it moves up the judicial ranks.
In the Batman universe(even nolan has to play), the mentally unstable costumed folk end up in an Asylum. Hell even Falcone ended up there.
To think joker would stand trail for more than 4 days is beyond anything in the comics...and for good reason.
Stephen Lang for Cable, Magneto or Slade Wilson. Take your pick Steve.