Is that what that little cutscene was before you go to the Lakebed Temple? That took place after the CoH, but before OoT.
Not that I actually understood what was going on in that scene anyway... :P
Plausible, but we're not even sure that the Twili exist on the AT. The Mirror of Twilight and the Twili race were created between MM and TP. How could they exist on the AT?
The Goddesses split the CT Triforce at Ganon's Execution when they granted Ganondorf the ToP so he could survive. So I agree with you there. Then the other two pieces went into hiding until they rested in Link and Zelda.
But, no, I do not believe that Veran is a Twili. The Twili were...