His future is definitely at CB i'd say. As for the best prospect, I don't know how you compare the potential of a young CB to that of a young attacker or a central midfielder, but the club rate him very highly, and rightly so.
Is he staying on the tour? Usually around this time in pre-season, most of the younger players leave the first team squad to accommodate the players returning from International duty. Reckon he might miss out on the US tour.
Not definitely, as there's nothing to commit him to signing for us. I think the fact that he's been brought on the tour and allowed to play is an attempt to get him on side for when he turns 18 in September. Then he'd be ours, but getting him a work permit is another issue in itself.