So you're absolutely right, better to ask what is proper etiquette WITH ANY CULTURE
If you live in the US and are an executive with a multinational corporation, and you still have to ask what is proper etiquette in dealing with a highly educated and well-traveled black man, you are either 1) clueless , 2) a Republican or 3) a racist.
Believe it or not, you'll never go wrong by just treating American people as people, regardless of their skin color. It works surprisingly well. On the off-chance that I encounter a black person, living as I do on the near West Side of Chicago, it usually turns out that they're generally regular people who laugh at funny sitcoms, enjoy well-made movies and good food and think the Bears should fire their entire coaching staff.