I was wrong about AC grounding! Chassis should be grounded
After the discussion of AC grounding in the Electrical Help thread, I researched the subject, because it's not one where a person can really afford to be wrong: I was wrong. Only the neutral should be floating in an RV, not the ground. The AC should be grounded to the bus chassis , and for precisely the reasons that folks gave. Grounding the AC to the chassis provides some protection against electrocution caused by a short.
AC should be grounded to the bus chassis!
I need to go back and run a ground wire from my distribution panel to the chassis.
Neutral should NOT be bonded to the ground anywhere in the bus.
The answer was in the book, plain and simple, but for some reason I got it into my head that both the neutral and ground should be floating.
So, thanks, y'all for potentially saving my life (or someone else's).