I agree that a wiki would be useful. But many of these questions are naive.
My Airbnb experience is that any detail not mentioned in the listing is not included. For example, I was charged extra for parking on the street in front of an AirBnB in a residential area 5 km from MIA. On another stay, I asked if I could drop off my bag (no early check in) en route to touring Venice. Denied. Expect nothing and you won't be disappointed!
IMO, the best advice I have is always travel with the phone number (s) for customer service in San Francisco. I have had to use it in NYC and it works! i.e. I called them, explained why the accommodation is not up to standard, and they fouond me a better alternative nearby. Also, take photos. Invaluable if you are asked to justify a refund request within 24h of the check in time!