Ooops… my embarrassment, I somehow missed Greg’s comment that this is a dead issue.
Well, let’s not say dead … only sleeping. I still appreciate the advice. They had intended to pay me a part of the salary “officially” and the rest to an offshore account to avoid Vietnamese taxation. On the local part, they said I’d have to pay 10% tax, and they didn’t mention Vietnamese Social Security at all. Maybe it’s good I turned them down!