Don't forget humor
Humor does NOT translate well across languages or cultures. This tends to be a fallback when things get tense, but can actually make things MUCH worse if the joke bombs (or worse, offends).
Idiomatic language is something to also stay away from. The author mentions his Kentucky roots; I'm from the NY/NJ area. There are many sayings (and individual words) that I use in casual conversation that don't appear in any dictionary (except for, perhaps urbandictionary.com).
I've worked all over the world (primarily Europe and Latin America, with side-trips to Asia). What I've learned: keep the conversation bland and speak slowly and clearly.
