Third, the concept of the lethality of a maxim isn't a principled or reasonable basis for restriction of FA arms
Is the argument that the lethality of weapon, in general, is not a reasonable basis for restriction? Or is it that of a FA vs. a shotgun or a 50 BMG rifle?
That leads again to the argument that WMDs are ok for the general public. If you say NO - then you are arguing the specifics of FA vs the others and doesn't that become a matter of risk analysis and empirical evidence as compared to some absolute principle?
As far as the Brady business - that was introduced as an argument accusing folks of arguing for some FA restrictions of sorta being Brady-ites. We see it all the time on lists - not a true believer, you are a BRADY. Let's let it pass for the moment for the theoretical. Are there limits?