In FFTA there was a sidequest that got you Cloud. I think something along those lines with maybe Tidus or something would be nice. Exept this time he could be made useful. Just a thought at least.

And also I dont know if its been mentioned, but what about airships and a possible pilot class. I know they werent in the first one, but they could have been developed within the timeframe.

Anywho thats just my two cents.