Ahhhh, I see. That is interesting. Hmmm... (ponders) If he is alive, would he be wandering around armless? Or would he have been reborn?
I don't know why they need the arms unless it's because Sanzos use their hands when praying? If you need the flesh of a Sanzo, I don't know why you'd specifically need an arm otherwise...
As for Nataku, I think he's in a coma/sleeping/whatever. He coming back into the picture will most likely lead to Goku regaining his memories and all the following conflict. Unless that is just his body sitting in the chair in heaven, and he's already been reborn on earth. I think he'll be back in the story, either as himself or as his reborn self. (theory)
Re: *Technically* out of the picture
I don't know why they need the arms unless it's because Sanzos use their hands when praying? If you need the flesh of a Sanzo, I don't know why you'd specifically need an arm otherwise...
As for Nataku, I think he's in a coma/sleeping/whatever. He coming back into the picture will most likely lead to Goku regaining his memories and all the following conflict. Unless that is just his body sitting in the chair in heaven, and he's already been reborn on earth. I think he'll be back in the story, either as himself or as his reborn self. (theory)