Idea sounds great. The problem is going to be similar teams that end up in luck. Baton passing will be awesome, as I doubt someone will carry a pokemon just for hazing or phazing.
But sign me up, and as for me, I like the 2a, 2b, 2c thing.
And just a suggestion, perhaps limit the base stat totals of the three pokemon, because I see a lot of celebi (600), t-tar (600), metagross (600), zapdos (580), etc.
If say you said the most base stats of the three different types of pokemon would be something like 1600, then it would eliminate some of the gay 1800 base teams, or more specifically, prevent everyone using the same powerful Pokemon. Nonetheless, this is just a thought.