Some really good ideas in here.

I had been thinking about Blizball, but the prposal is hard, because it would need to be changed from the turn based model that was in FFX to real time 5vs 5 pvp game, and I haven't yet come up with how that could be done while keeping the same feel of the game, but as the pvp skills are already on it's own section, i think the same model could be applied here, now, about the actual gameplay, I find that harder to translate.

The other thing, but that will probably come with teh casino, is the card game, Triple Triad, Tetra Master... whatever.