There should have been one crown and one tiara for prom king and queen, not two crowns.
Sue Sylvester says to Artie that if Puck gets expelled there wouldn't be enough people in the glee club to compete at Nationals, but at that moment there are 13 members and it was well documented that they need 12 members to compete so even if Puck got expelled and couldn't compete they would still have enough members.