I would agree with Mike that it's definitely too hot in some of them, and I think the fact that it's seem warmer than the other lights, is what bothers me. I typically see rim light as being color neutral to the overall lighting, or often a bit cooler.
Rim light to me, is anything that come from behind the subject and hilights any edge of the subject. But looking at these photos, I feel like rim light from the side works better when it hits the edge of the face/neck/ears, and not so well when it hits just the side of the hair. The last few of the girls, the rim light only highlights the side of their hair, and a little too strongly. It looks to me, like if the light is only going to hit the hair, it should be coming from a little higher angle. When it highlights the face, I think it looks nice from the side.
I think the one of the boy in the glasses is the best one.
On of the other things, I notice, especially in some of the wider shots, is that your rim light doesn't seem very controlled. On a few, it is spilling all over their shirts and pants, which I think is too much. Maybe some more careful feathering with barn doors/snoots/grid spots would help. Sometimes it works best to actually shoot hte light over their head, and let just the feather kiss them on the cheek, so it falls off pretty quickly down their neck and torso.