GasparZizou
Super Freak
I think the character should have started out that way, with no killing rule, then drop it. I can't see how in the comics after repeatedly catching and bringing the same villains in to Arkham makes any sense. Joker in the comics has come back like what? 20 times at least? Same for Penguin, Riddler, Two Face, Freeze etc... It just doesn't make sense in my eyes to keep him that way.
1. People mistakenly put the blame of villains recurrently escaping on Batman, it shouldn't be so.
2. Killing isn't your right, nor your duty, an idealist Batman who's driven by the sense of Justice wouldn't kill, Cap isn't driven by Justice, someone put the Marvel Universe this way once, and I think it fits: "Marvel's aren't superheroes, they're just a**holes with powers", I think "a**holes" in the way of flawed, everyday people, whom aren't beyond or above killing, which is one of the fundamental differences between the 2 houses.
You mention how Batman villains come back all the time, well, don't Marvel Villains too? Despite the lack of no-kill rule?
Now I don't disagree entirely with you, I think the only one who should have a no-kill rule should be Superman, and maaaaybe Flash and WW who have the physical capacity to rise above that moral standard, but Batman? It feels to me that in decades of crimefighting, Batman would've put himself in a kill or be killed situation a couple times, where his life depended on self defense.
It should never be a choice imo though.