Right-O; thanks much for your thoughts...
It would be an easy programming change.
And perhaps airbnb might not draw so much fire from hotel/motel industry battling its operations in courts, e.g., New York and other places....
Beyond that, "arrive" and "depart" convey a very different sense for persons arriving to stay at people's homes, and for the Home Owners themselves (us) also.
And, especially among relatively new airbnb travelers, the "check-in/out" hotel jargon seems to misrepresent what's going on and to cause confusion. (I'm not at a desk "checking people in!" It's my HOUSE -- i Live here !) ....
Thanks again.
channahsorah.