This ended up being a much longer read than expected. I love a good villain-cosplays-as-superhero-and-ruins-public-goodwill-for-him trope but what I think is most interesting about this volume (other than being the origin of the batmobile AND the bat signal) (bruce walking back home in the daylight has to be one of the funniest frames I've ever seen) is the proximity of Bruce to murder and what it actually means to him.
This volume, above many others, spends a lot of time analyzing Bruce's psyche and why he is the way that he is, by the virtue of Dr. Hugo Strange psychoanalyzing him and psychologically tormenting him. Everyone knows Bruce is against killing people, but in this volume, the cops kill again and again, and Bruce is not against this display of what he believes to be justice.
Given the digging up of his past through hallucinations, my hot take is that Bruce actually doesn't believe murder is evil, per se, because if he did, I think he would see how killing some of these villains would result in less murder in the future (which you would think a vigilante like him would conceive of pretty early on) or he would, at the very least, have a problem with capital punishment/the police killing people without trial (like they do to the Night Scourge, who could have been forced into this, for all we know).
However, it's made clear that Bruce doesn't care about police or other heroes or anyone that he considers "good" killing people. He only has a problem with HIMSELF killing. That can boil down to one of two explanations-- either he doesn't believe himself to be good on an intrinsic level, or his reluctance to kill has nothing to do with morality at all.
If it's the former option, that provides a very interesting lens to look at Batman comics through-- does Bruce see himself as a bad person committing necessary evils to protect innocent people, and he's just afraid that if he kills, it would not be a morally protected choice? Does he believe only "good" people can be justified in their murder?
Or, if it's the latter option, then I propose that he does not see murder as a moral act, but rather, a trait that distances him from the murderer of his parents. It's a wall that separates Bruce from his own trauma, not a moral status.
I tend towards the latter explanation, but I'm excited to see how the other volumes change my opinion on it.