Also, Hair loss is a symptom of radiation poisioning, radiation levels in the Captial wasteland are clearly higher than in Cali - It isnt a breach of canon to follow what we know about radiation sickness.
Considering that everything that doesn't work in real science, is explained with SCIENCE! and the concepts of 50's understanding being actual fact, then this is exactly a breach of canon.
Regardless of whether radiation made the hair fall out or not... The original molerats would not have looked like that if their hair came out... These molerats were obviously modeled after the subterranean species you mentioned first.
Again, Complete nonsense. Its a shiny item, a bottle cap isnt that different from a coin (metal, round and shiny). People like shiny items.
The concept of currency in many cultures typically come from a common source - a certain, pre-measured amount of shiny metal certified by some important figure somewhere by mold; Not only that, we see Concurrent development all the time, even in recent history - key elements of Manned flight, and even the lighbulb have "Disputed Inventorship" status as different inventors played around with the same things.
If its conceivale for one post apocolyptic proto-civilisation to adopt one currency, then its arguably more likely that another would choose the same thing, because the circumstances in the choice here are exactly the same (Relatavely abundant and portable item, easy to ascertain value, not produced any more so impossible to counterfit).
People are smarter than birds.... Just cause it's shiny don't cut the mustard.... If you want to go on the rational that bottlecaps are prevalent and light and kinda look like coins.... How about real coins.... I can assure you that the US mint has massive numbers of real coins in circulation... Certainly enough to continue using for hundreds of years after 90% of the population is destroyed...
While your mention of disconnected inventions holds some water, I would point out that manned flight and lightbulbs were very different in concept than the final product.... Think of all the flapping wing attempts at manned flight... While this would lend itself to the argument that disconnected societies would conceive of replacing currency at the same time, the odds of them both choosing identical items (that don't have a history of use in barter or a history of any real value) is beyond astronomical....
As for Harold... I can see nu_clear's points about the advancment of lore... And although I still say he'd have never made it across the continent, and that his tree has grown far faster than previous games indicate (thus existing lore), I will retract him from my list.
As nu_clear points out, things like exploding cars are not referenced in previous games as NOT exploding, I'd say the implication is there... The quest line in FO2 heavily suggests that ANY working car parts are few and far between.... In terms of what FO3 tells us... In a world where mutants and critters and raiders are a constant threat, explosives of any kind would be rather coveted.... Why is no one scavenging these apparently working fuel cells...?
For that matter, why haven't the ghouls outside Tenpenny Tower used them as weapons... Or the raiders.... or the Enclave....?
All that being said... I have played hundreds of hours of FO3, will continue to until NV comes out, and just enjoy the discussion as an excercise in critical thinking, so don't get too offended if I'm challenging you.