I think you explain the Skybreakers disposition very well, but I'm not sure that I agree regarding Szeth. From my view, Szeth doesn't appear to care for laws or what is Just; what he does place above all else is the dogma of his religion, which he follows to the point of insanity (hence, in my opinion, the Vorinism ideals that Szeth exhibits notably are Piety and Obedience). One can argue that Shin's religious precepts are laws in their society, and while that is true, Szeth's act of placing his punishment as Truthless to supersede law is difficult to reconcile with what we know, little as it is, with the Skybreakers, who seem to respect all laws equally.
I do agree that Szeth is a fascinating and interesting character though.