If i can interfere with some Krall's ideas : i think you made a too much civilized post-apocalyptic UK.
Too many important cities just rising from their cinders, too many organised settlements.
What its interesting in Fallout, at least in West Coast (less in Eastern one) it was that cities would have likely disappered and let only tribals if the absence of rain, the desertification wouldn't have striked.
But as the major cities were almost completly destroyed and at best became sort of champ of ruins with distinctive settlement not claiming to be the heir of the pre-war city (No settlement in CW claims to be "Washington", no one in the Boneyard claim to be Los Angeles, etc.). But smallers, less interesting cities survived as Klamath, San Diego (Dayglow), Barkesfield (sort of), etc.
The only settlement that continued to claim thesmelves as the original cities are fews (i can only think of the Pitt, New Vegas or Ronto). Besides all of these cities, at the exception of the ones quoted here, not really persued their pre-war role.
Klamath is a trade center when it was more technological or small industries centered pre-war, Goodsprings was only a touristical ghost city and became a point in the tradeway because of its waters.
Aslo, for the rest, you're making too organized factions. Republics, cities states, democraties, etc. I mean maybe you can have some municipal powers (not really democratics, not really autocratic, like Junktown, Megaton or Primm), but cities states and critically republics need to be very very rares. In the known fallout-verse i can only think about the NCR, the Vault-City and maybe the BoS of Middle America as organised states (well, with the Republic of Dave too).
On the other hand you need more caricatural organisations. I don't know, City's ghoul in tory uniforms trying to rebuild the ruined business town. More seriously, the Wasteland is very practicable for organisations growing powerful and trying to gain to their cause the fews settlements.
It's how NCR passed from a small redneck village to the most enviable state in West Coast.
More ev0l ones too. Muties, BUF led by the black grandgrandson of Mosley that try to eradicate ghouls, people venerating an advert animated panel that advise them to kill people...And of course, raiders. Many raiders.
And the Wicker Man as a spreadful religion