Is there a logical explanation as to why Batman essentially just slapped Scarecrow on the wrist in the beginning of the movie? "Don't let me see you here again..." He was part of the plot to destroy Gotham, and Batman doesn't turn him in to the cops?
The main problem is comparing Katie to Maggie. Katie's Rachel was the girl next door, and Maggie's Rachel seemed to be more distant. I thought Katie was fine in BB, and I missed her in TDK. I think that Maggie's Rachel was given too little to do to make Rachel her own. When she died, I didn't...
I'd chalk it up to him being shocked and not knowing how to initially react. I think the best way to convey a "huh?" reaction would've been a shot of his face, but with that mask on, it wouldn't have come across very well.
Now that you mention it, I think I get it now. I got confused, too. I think Batman was intending to save Rachel, but the Joker did switch the addresses. Later in the movie, the officer gives Gordon's wife the address to the place where Rachel was killed (as mentioned by Harvey)...255 something...