I think it's smart to take steps to keep mites out of your collection, Zina, and that's not paranoid at all.
Years ago, a bunch of snakes in a collection I'm aware of were killed by a mite-transmitted disease that a friend brought into the collection after spending a day at this very reptile expo (which could happen at any show, I'm sure). You really can't take it for granted, and it's best to be careful.