Even with my issues with this movie I think it gives the best treatment to Batman's "no kill" rule we've seen to date on live action film. At least as far as i can remember.
Keaton Batman is basically an 80s action hero and it never comes up.
Bale Batman states that he doesn't kill, scolds other characters about killing, then TOTALLY kills people without it being addressed.
Affleck Batman doesn't directly address it but it is mentioned that his tactics have changed (not in a good way) and he does seem to associate (at least in my interpretation) the final blow he would have struck to Superman with the murder of his helpless mother.
I honestly don't remember if it's addressed in Batman & Robin or Forever.