"I've started to like the new characters because on this episode I realized what they were: a new "riff on the wonder twins. And that's cool."

That makes sense to me. Great observation.

"Hiro being Kensei would have been ironclad if white kensei hadn't healed Claire-style. Actually, that explains how kensei could cut out his own heart and still live to profess his love. So, I'm betting on Amalgam Kensei, the stories being about the exploits of Hiro AND white Kensei."

I also see Hiro falling in love with the princess to complicate things. I think you're probably right about amalgam Kensei but I wouldn't bet against it being mainly Hiro either.