I received a note about using "asshole" in Chap. 45. It's an Americanism. Aussies and Brits use "arsehole."
English-speaking Canadians are too polite to use either.
Years ago I was chided for being overly Australian -- seemingly most readers speak North American English. I'm now at a loss as to what I should use.
I have -or/-our and -ise/-ize problems, too. I've given up on most uses of -re as opposed to -er (except I do tend to employ theatre).