I entered the PWT for battle points to get the power anklet, but these trainers are really strong. The only ev-trained Pokemon I have is Jolteon, and it has: 255 sp.atk, 1 atk (not on purpose), 254 speed. And still, Lt.Surges Raichu was faster.
Yes, all PWT trainers have EV trained Pokemon. These are programmed by the game.