As a Brit some of these seem fairly universal, "no offense" for example. Although my Grandparents don't say it before announcing something outrageously offensive, I just put that down to mental filters breaking down due to old age. There also needs to be a section on Americans aversion to discussing bodily functions. "restroom", "powder my nose"?
"restroom" Is "loo" any less ambiguous? Speaking of Brits, they did point out the perils of faulty phrase books many years ago: https://youtu.be/bNP7uQQT-oo
Even then only the poshest people talking about going to the loo. I've been in pubs where somebody has loudly proclaimed that they were "going for a dump, I'll be a while" and I have lost count of the number of conversations I've been party to in public about pissing, shitting, wanking (masturbation), or shagging (having sex), that would definitely not be welcome in American settings. Also, we say cunt a lot. Like, a lot.