Actually the Bedfordshire/Hertfordshire accent is pretty much a standard english accent, a bit less snooty than the upper class accent but if you don't have the ear for it, you might confuse us with those Lords and ladies
.
As for the humour (yea I added a u, I'm one of THOSE englishmen
) I'm sure you guys will be fine, it's not like we joke exclusively in cockney rhyming slang or anything.