I'm surprised that you put Gun Ownership in the Scummy list.
While I don't own one myself, a lot of folks I know do. However they take responsibility as gun owners.

Perhaps a general characteristic of scummyness is simply "Irresponsibility". To my mind, that covers lying, infidelity, non-payment of debts, self importance, the attitude that "The ends justify the means", ingratitude and bossiness.

I'm not at all sure if that's the question your asking though.