So is opening with "bonjour hi" considered more correct (or maybe just more useful?) than opening with "parlez-vous anglais?"

I've found in German, French, and Spanish speaking places that asking in the language if they speak English gets one a little farther than just starting in English, even if that's all the non-English one knows.

(Except in Iceland. As far as I can tell the expectation there is that one start in the language one wishes to continue in, and one can sprinkle in one's handful of Icelandic words later.)