Some Ideas
Well, we could have random submissions. Submissions can go to one of the mods or one responsible member, and that member would post all the submissions in a thread. I don't want to participate this time, and I'd love to be a judge. Actually, it'd be cool to have an American Idol-like voting, where members get one vote and the judges each get one. Also, another idea, if we have a LOT of teams, we can eliminate one team each week. Winner can get extra points and some kind of advantage (maybe an extra day to work on the project).
Solution to the team picking is to randomize it. We can make a list of all the players in an excel file and just assign people numbers (1-5) and then pool all the 1s, all the 2s, etc.
If new players want to join, they have to wait till there are enough people to create a team, though they'll start with a handicap.