It will probably be busy, especially at camp spots. Yes, there is no reserving camping, either on the river or the camp sites at the river access points that I know of. You COULD walk most of the rapids if you REALLY had to, but it is really all class II. I think it would be faster and easier to swim than to walk, so why not just let them try paddling them? It is definately a beginner section, especially at late summer flows.
It takes a big man to cry...It takes an even bigger man to laugh at that man.