score:9
Airbnb is not completely illegal in NYC: they can legally do short-term rentals in "properties where no more than two people are hosted, the host resides in the dwelling unit, and where guests have access to all parts of the dwelling unit, according to the city" (Guardian)
Since you're renting a full flat, presumably your host "resides" there on paper as a way to skirt the law. Odds are the biggest risk to you personally is this that Airbnb preemptively sweeps sketchy-looking listings off the site, but if this happens you would get a full refund. However, you will still need to find a new place to stay at short notice.