Yes the US Virgin Islands has an olympic team.
There are 529 athletes on the 2012 US Olympic team. There are 268 women and 261 men.
Yes, he was on the 2000 US Olympic Basketball Team.
It depends on what country you are talking about. The 2008 US Olympic rowing team had 45 members.
At the olympic trials Look it up on google or something else, or go to the olympic homepage.