Always multi-ways mixed home game strategy (nlh, plo, plo8, stud)

I got invited to a mixed home game that plays NLH, PLO, PLO8, STUD twice to three times a year.

Is there a winning strategy to this game and minimize variance because the stake is bigger than my bankroll?
(BR 40k, stake 10/20 in my local currency)

The game is always multi-ways, and it is hard to isolate almost everybody's buy-ins deep (around 200 - 400 BB).
The atmosphere is a party game, and they love to gamble in every drawing spot, such as inside straight, four outs draw, etc.
The game is chosen by the player who wins the pot (not fixed by hands or time), and they usually choose PLO.

I want to win the game and also be a nice guy on the table, so I don't want to play too seriously (or too tight) and give some action.