That's kind of the background I had loosely formulated, too--I had this image of the Airbenders as a rather fluid group. I keep trying to figure out if there WERE Air Nomads who weren't benders. If there were, maybe the temples were where benders went to learn their art? Or maybe they were more inclusive boarding schools. But yeah, I am totally with you on the loose basis for relationships and communities--it just seems so natural for people whose symbol is the wind. ;)