Funny enough, a real world Batman would kill people just by knocking them down. Since knocking people unconscious will more than likely kill a person or severely damage them . In keeping with the topic, yes Batman is insane, but insane in the sense of being severely
mentally deranged. No matter what, even in a universe as fantastical as the one Bruce Wayne occupies it certainly is a crazy idea. Batman is also crazy in the sense he endangers little kids by having them assist in his crime fighting, wearing their underwear in public with a domino mask. Even after the murder of the second kid sidekick, he still willingly allows kids to assist him.