Ah, sorry, my bad syntax: Tamayori should have been the active participant (in the post) throughout. Though I can see the lucky chanelee of the hour being referred to, during that time, as Tamayori--which would also dovetail nicely with Tamayori=miko, wouldn't it?

...so if Leia had learned to use the Force by ROTJ and was the one to supernaturally impress the Ewoks, would that make her the Witch of Endor?

Sure. She'd have been able to call up shades of the dead & everything, just like Luke. (The Dathomir witches? Eh. I barely remember the book anyway, but I think they were just descendants of stranded Jedi or something.)