Is this one of the best opening setups for FFA?

https://www.chess.com/variants/4-player-chess/game/35434709/138/1

you put the king in corner and advance pawns while keeping your king safe with same color pawns

as long as you can manage to lock pawns with your side player and then move king there you should be safe

also make sure to keep a bishop fianchettoed or else you're probably dead on diagonal

Thats what I play normally

wait what going on???

Well, as for me, green made slight positional mistake with l5-k5. You should never allow your left-side player be safe, if you can.

i mean i usually move my king to the left because it's easier to coordinate pawns to promotion, so yes i'd lock the position on my left, even if it means my left also being safe

What if he took your Bishop 6.g? this wouldn't be an ideal position. 

Maybe Neg2 with left side pawn pushing would be fine but it's not the best

Or just wait, only push j3, after they push l4.   2300's will almost always take your Bishop. 

If I may, I'd like to interject something here. This note is basically for lower rated players who get into a game and see you're surrounded by players 300 or 400 points higher than you are. Don't abort the game. You have the chance to learn something by playing the game out. Don't be put off by the temporary alliances, ( or temporary teams if you will ) watch the moves and their order.  Push your King's pawn and your King's Knight pawn 1 space so you can fianchetto the bishop. Watch out for Queens and bishops and their attacks from long range. Try to learn, if you get knocked out early, stay and watch the rest of the game. 

Note that unless you are 2300 and are playing 2600 players this doesn't really work since below that level people are trash (myself included)

The "don't abort" part i agree with solely because of how bad these players can be at times