I don't have a problem with comic characters killing people in their movies, if they're just as likely to in the comic book universe. Now, when I say that, I mean that I think it's only logical that guys like Batman and Daredevil would end up snuffing some lights if it came to it. The movies aren't limited by the narrow editorial vision of a child's franchise. They must be allowed to explore the characters beyond the rules of a comic book. So, I loved seeing Keaton take some fuckers out. I dug that Daredevil isn't afraid to spill a little blood (although I agree about the uneven-ness of it all). What I hate is when a character is forced to have to get around the killing stuff by, what is so obviously, an editorial decree, rather than the flow of the fiction. I think Batman Begins trailed that line pretty perfectly with Ras at the end. I like that he didn't save him. But, on the opposite end of the spectrum, I think any Wolverine movie that isn't rated NC-17 because of brutal violence is weak. For characters like that, they should always be true to the nature of the character...
