A "Pro" athlete makes a living by playing a sport. Technically, I don't think there are *ANY* Pro paintball players. Ollie and Lasoya are the closest, but they are not paid just to play; they also have regular emlpoyment duties with their sponsors/employers, so even they arn't pro in the strictest sense.
You do *NOT* need to be paid to play to be a Pro athlete - many pro athletes are Pro based on PRIZE MONEY, or better yet, ENDORSEMENT DEALS. This is especially true at the top of major sports; top athletes get a lot more money in endorsement deals than they do from their playing salary.
In PAINTBALL, 'Pro' really means 'Expenses paid'. But, that's true at the D1/D2 level for some teams.