Well, as to the American spelling, as an American doing a PhD in Britain, I will say the spelling can get confusing. I do try to write, spell and think in British English when I am doing my PhD writing--one easy way to cope is to set the spell checker to UK English. Then there are some definite "British" turns of phrase and of course of punctuation ( those should have been inverted commas in the British style). British English lists things out as, firstly, secondly, thirdly--this is not American English.
For me the problem is the reverse, when working on American English things ( like for work) and British spelling and phrases creep in...