ACA mandates that ~80% of insurance co. revenue must go back towards medical service. So not "non-profit" per se but there is some kind of restriction there.
2) Not for plans that are (IIRC) two years old or newer. I'd be shocked if there aren't a bunch of shenanigans going on with this loophole.
(2) and (3) were part of what I meant by a lack of regulatory bandwidth in another comment. There are rules that could be enforced to promptly impose steep penalties for a company that tries to skirt them. But they just aren't, so after one company starts doing it the rest inevitably follow suit.