I never really thought about this. I don't have any big contradictions to what you said, so I'll agree with you.

I don't know if FD Link is the Termina counterpart of Link. I always thought the mask simply enhanced a person's abilities. By making Young Link and adult, and giving him a big sword. I'd rather believe Link's counterpart to be the FD than Tingle, though.

Tingle is Adult Link's Termina counterpart.

J/K. I don't mean that.