trying to explain how Batman would work in the real world is silly. He wouldn't. He'd be killed shortly after the start of his career as a vigilante. Hardened criminals with big guns aren't going to be scared of a guy in a bat costume with clever gadgets. And it would be impossible for Batman to ensure that he wasn't actually killing the criminals he fought, especially while fighting a group of them at once while his own life was in danger.
Leaving aside the issue of how one guy randomly patrolling the streets and beating up thugs for a few hours a night is actually going to make a big difference. When it comes down to it, Batman's as much fantasy as any other comic hero.