Yes, the Batman thing definitely goes back and forth over the more than 80 years he's appeared in comics. Hell, he used guns in the wartime movie serials, runs cars off the road, etc..
Superman is far more rigid in his "no kill" rules, though he has also gone off the rails on rare occasions. That's one of the reasons I so dislike "Man of Steel"; it goes with the exception, rather than the rule.
The thing that made me realize that they'd really missed who Superman is in Man of Steel was the scene where he steals clothes off a line.
Him killing Zod to save everyone around him? That I can see- a regrettable necessity to prevent massive loss of life.
Him stealing clothing for the sake of convenience? Oof.