Well from all these ideas, my idea of a FFX-3 would be with new places and old places, even in the old places there is something new.
YuRiPa, the three hero's start out like this,

YuRiPa in Mihen Higroad (in different clothes not nasty clothes)
siting down and talking about the pass and what to do next, the sunset is out and Paine laying down, Rikku laying down too facing the sunset and Yuna siting crossing her legs.

Thats what I think is a good start in FFX-3