Yeah, ok, so, help a newcomer to AirBnB out: how far in advance should I book a room, and what string of slightly annoying nudges should I sent to my host so that I can verify by their handling of my annoyances that they are not going to pull the rug out from me the day I arrive in their city?
For us, book as soon as you know you want it. We've had people book several months in advance and we make sure to honor them (the "worst" that happened is that somebody got the whole house to themselves for the last few days of their stay while we were in France).
I would just ask what the check in procedure is. If they are on top if it then they will have one. Also, again, look at the reviews. If someone has had a dozen guests who liked it enough to review then you know that they are serious about it, and canceling on a guest would completely ruin the reputation of someone like that.
We would only cancel on a guest if we physically could not host them (room was on fire, etc).