I just saw Fury Road and I'm definitely down with your headcanons. Especially the one about Miss Giddy.

I wondered also if there's going to be a backlash against the people who were "privileged" under Joe's reign -- what people then take out their pent-up rage at her and the others who used to be close to Joe? Their hailing of Furiosa as liberator suggests not (and I hope not), but it's going to be a looong time before the Citadel resembles anything like a functional society.