So a friend and I would like to drive up to Worlds with our sons to watch the X-Wing and Destiny finals on Saturday and Sunday. Are spectators allowed at these events or do you have to be a player?

The Game Center is closed to anyone who is not a Worlds Participant. So no spectators (who are not playing in some other game).

Are your sons minor children?
If they are, you should be allowed to accompany them at The Game Center.