Thought I'd just report back from my NYC trip
You can use airbnb in NYC as long as you're renting a room not an entire apartment.
We rented a room in Brooklyn and it was amazing
We used the subway to get from JFK, to Brooklyn and then in and out of manhattan every day, never felt unsafe, New Yorkers were so helpful if you looked lost, we travelled at midnight and trains and platforms were still busy.
Best things: the highline, the magnum factory and the 9/11 museum