The leap in difficulty from Group 1 to Group 2 was rather... substantial, in my opinion. I could answer 85% of the questions in any of Group 1's categories, but I struggled with a lot of the stuff in Group 2. Though seeing as how you separated the groups based on age, I can understand why.
I think hand-raising would have made the game a lot fairer in the long run, especially seeing as the person sitting closest to the mic had a decent advantage. Even better, if at all possible, get one of those buzzer devices. I can't be sure how much they're worth, but they would be really useful.
Other than that, it was a fantastic panel. Full of fun and amusement!
Finally, "5000 points taken away for making a crack about the Star Trek category being all about Stargate!? THIS IS MADNESS!"