I would like to repeat my suggestion that we go with two teams for this one. Here is my case
1. We have enough interested players to form two teams right now. We can start the game and recruit more players as we go. We just don't have enough interested players to form 6 or even 4 teams, let alone find 6 turnplayers
2. With two teams we can play sequential turns, so there won't be anymore doublemove controversies.
3. With two teams there will never be a mismatch where one team gets ganged up on by the others.
4. With tech trading off there is no possibility of tech alliances, so there is less of a need for inter-team diplo anyway.
5. With 2 teams we minimize the risk of running out of turnplayers, and maximize the amount of interested involved players on each team having discussion.
6. We all know that it is inevitable that the game will end up with two unbreakable alliances anyway, with 2 groups of two or more teams acting effectively as one team, so we might as well just start off with everyone on one side or the other.
Points:
With two teams, we could have one team that is a Merlot style Monarchy/Republic, and one team that is a Democratic/Anarchic style team. People can choose which to join.
There is still the possibility of some inter-team diplomacy, especially if we add some AI civs as buffers, trading partners or tackling dummies or whatever. The humans can cooperate to kill off the AI, then turn on each other or do something else.