Tripod Tom: For tournaments where you play 1 game with each player in your section, you need 5 open slots (regardless of how many people per section) and for tournaments where you play 2 games with each player in your section, you need 10 open slots (again, regardless of how many people per section.)
And Yes, for single elimination, you only need 1 open slot..

And I am buying some bishop memberships for pawns tonight, so I will include you.