I think Rachel's character is supposed to be very complicated, at least in relation to Bruce. Nolan, for one, said that he thought the story needed someone who knew Bruce from childhood, who knew the same tragedy he did (i.e., seeing him deal with his parents' death), who went through his ups and downs. Batman doesn't have that type of "friend" in the comics - unless you want to count the "Hush" storyline -
Mallory Moxon was portrayed as such during Ed Brubaker's "Zeiss" storylines.
What makes the character more complex it is that she's a woman - so love comes in, no matter what.
I don't think that's really all that complex. What gives her any complexity is her interplay with Batman, but she never even questions him, so all that complexity is lost.
This is movie, and a comic book one at that - Bruce needs a love interest. With Rachel, Nolan is able to avoid having a "chick of the month" Bond babe thrown in for the hell of it just to have a sex angle.
I suppose. But "chick of the month" is an aspect from the comics. Bruce never has long relationships, because it's difficult to maintain any kind of emotional stability as Batman.
I'd argue that recasting Maggie as Rachel will only further make this feel like "another new love interest".
I think Nolan had the whole "potential romance" at the end of Begins because not only does it keep Rachel relevant (besides Harvey Dent coming into the picture), but it also nixes the pressure to hire arm candy to be the new "Batman love interest" these films used to have.
The love interest in BATMAN was Vicki Vale, and she served the story. Ditto Selina Kyle in BATMAN RETURNS. Ditto Chase Meridian in BATMAN FOREVER. None of them were useless. The only real pointless love interest in the franchise was Julie Madison, and she was played more toward Bruce's playboy side, and less like an actual love interest.
Even though Rachel isn't comics canon like a lot of the other characters, it allows the film to have a serious female role and a love interest at the same time. I couldn't say that for Schumacher's Batman (or a lot of other action films.)
Vicki wasn't serious? Selina wasn't serious? Chase wasn't at least a little serious?
I agree that the "love" angle seemed a little wooden at the end of "Begins," but I think we all saw it coming. It's reasonable to believe Rachel could fall in love with Bruce, even though they're "just" friends. He's single, good-looking, rich, and has a respectable quest for justice going on - stranger things have happened. What we really don't know is what Bruce feels for Rachel - is it just friendship, or more? We know he cares about her, but beyond that...? This is something "TDK" can deal with - if Dent is truly courting/dating Rachel, perhaps Bruce feels jealous, and it complicates things even more.
The question is...at this point, why should we care? He made it clear that he doesn't think he can have a relationship with her, and frankly, Bale and Holmes had no absolutely no chemistry together, so anything between Bruce and Rachel in THE DARK KNIGHT is going to feel like it's coming out of the blue.
I don't mind the "friendship" angle, but the romantic aspects of it are just forced. I would have much preferred for someone from the comics to be the three movie long "love interest", not someone they made up from scratch. That would have seemed like the smart choice, at least.
Selina Kyle, perhaps. Make them childhood friends, and add yet another element of tragedy to things.