The fact that Rust felt his daughter's love in the "blackness" is an indication that you are right. And I did like that part, but on repeat viewings I think I became very nitpicky:)

The TDK reference is spot on - it's actually one of my all time favoites and I am considering doing an analysis of the trilogy - and I think this ending of Batman Begins signals who "created" the Joker. It was the Batman - Gotham had no need for a villain of his kind until the Batman appeared.

Jim Gordon: What about escalation?
Batman: Escalation?
Jim Gordon: We start carrying semi-automatics, they buy automatics. We start wearing Kevlar, they buy armor piercing rounds.
Batman: And?
Jim Gordon: And, you're wearing a mask. Jumping off rooftops. Now, take this guy.
[pulling out a file]
Jim Gordon: Armed robbery, double homicide, has a taste for the theatrical, like you. Leaves a calling card.
[shows Batman a plastic evidence bag containing a Joker card]
Batman: I'll look into it.