Re: How long did Nolans Batman actually fight crime?(SPOILERS)
Well, Bruce Wayne was never a people's person. Not in the traditional sense at least. With all the facade that he made as a "playboy millionaire" I don't think he would open to more established relationships in a broad sense. On the films he states "I don't have the luxury of friends."
The way I think of Rachel is that she represented an ideal of moving on. Even though Rachel clearly didn't feel the same way. That's where most criticism for the relationship is found in TDK. The truth is, there wasn't a romantic relationship. Bruce wanted it to be, but Rachel whereas Rachel toyed with the idea once, she found in Harvey what she thought Bruce could never give to her. But more importantly, they were still friends. They were close, and he lost her arguably because of his actions.
Besides, I see it more of a nod to The Dark Knight Returns, where Alfred continuously teases Bruce about his personal life. In my opinion it was better done on Rises.
But as stated before, there are multiple factors at play here. It's more that the sum of all the parts.