No, he was sane, :p, so were his parents...
As for the US, we have so much variety here regionaly linguistically, you can't just lock it down to one area of pronunciation.
If we go to dictionaries they actually list multiple pronuncations as being "correct", including "gra-ham" and "gram", :p.
http://dictionary.reference.com/browse/grahamMy guess its just subtle dialect differences from different regions. Linguistics can be complicated.
England and since Roberta has said that Daventry is supposed to be a place in England a long long time ago
Actually, she's never said that "specifically". The most specific quote she has ever mentioned on the subject is in the "quote" at the bottom of my posts... She doesn't specifically state its "england", although I can see how that could be assumed. It might also explain why they switched over to older English style in MOE...
If you went the Companion route, Peter Spear states that Daventry in England, as mentioned in Shakespeare has nothing to do with the Kingdom of Daventry.
That being said, the English, Daventry is still alive and well

. Archaeology could be interesting there, but people know where it is, it hasn't upped and disappeared. People know exactly where it is, its still thriving.
There is also an injoke in KQ3, where its implied that Daventry is in/near Yosemite, LOL. If you look at a peculiar looking mountain top.