Vip.rus, please read the rules carefully: many of your questions are already answered: regarding the number of games (2 games in 2 rounds = 4 games), it's not necessary for everyone to play against everyone else (with the proposed pairing system for 2 rounds, it's impossible for 2 teams to play each other in a way that ensures everyone plays everyone else), and no one will play 3 games.

Regarding the team composition, having 2 one-deck, 2 two-deck, and 2 three-deck ships is acceptable.
Initially, I wanted to introduce a system where different point values are awarded for winning against a player with a lower or higher skill level.

I think that 2-3 days before the registration ends, we will hold a vote. If there is no clear opinion among the tournament participants regarding the format of this tournament.
So, let's discuss and make suggestions...