Excellent. I wish there were more people discussing this - though, as it exists only on Bakker's blog, I can see why people don't read it. In the comments of each sequence, specifically the section with the hit and run, I believe there were specifics mentions of this inversion you're writing about.
In the Every Life Has a Nineteen thread, I mentioned that about half the books takes place before Dylan hitting *someone* with a car. So I'd wonder if all or, perhaps, none of Dylan's ruminations of about Cutter reflect your thoughts of rationalization.
Also, your post makes me curious. I've met guys like Cutter in my life - the scary ones are not always violent, but they're definitely the smart ones, while the vapid ones are just sometimes violent in ignorance. The one point towards Cutter being a sociopath is his reaction to Dylan beating him in the Acid Arm-Wrestling. Cutter betrays nothing, if I recall in that scene, Dylan is left with an odd "that was unexpected." But if deception and vulnerability is their game, then Dylan is both deceived and vulnerable following this moment, as it's his expectation of actually winning when he confronts Cutter at the end.
In the ELHAN thread, I did suggest something further wild, that Cutter is Dylan's rationalization of his own behavior. That It, Dylan, Cutter are all one.
Also, one other thought for you. There's a passage, which I don't have time to link at the moment, where there is a lock and key metaphor regarding brains and murderers. The idea basically is that because of predisposition, environment, and behaviour, the fact that you can only consiously affect a "BBT" portion of that interaction, suggests that there are certain circumstances that will see all of us murderers. Sometimes the complex interplay of life will key those circumstances, sometimes it won't. I know Bakker to be of Machiavelli's mind, that fortune (the complexity of the multiplicity of circumstances affecting each of us) governed half of what all we will do and all that will be done to us.