MTG Salvation

I just had a quick question as to what format of multi-player is EDH usually. My playgroup tends to play more 1 v 1 and when we get together we have a huge debait as to whether to play free for all, Star, Emporor, or some format of 2 or 3 headed dragon game.

From my understanding it is generally some sort of free for all format. My only complaint there is that I tend to be more competative in my deckbuilding therefore making people tend to target me out first as I have put more time and money into a lot of my decks. While I am all up for doing other multiplayer formats I dont like being targeted first all the time because my decks tend to win.

So my question is what format of multi-player is usually used when playing EDH?

Here are a few things I might consider changing:

OUTS:
Khalni Gem I worry as this isnt actually any mana accel. I understand you plan on blowing up most all the lands and want mana through other means I just don't like how this doesn't put you up any mana.
Sift there is better card draw out there
Concentrate there is better card draw out there
Breath of Life in my mind Miraculous Recovery is better. You could run both though I suppose.
Auramancer Not enough enchantment targets for this to seem viable to me.
Angelic Arbiter Doesnt seem as good as a Blazing Archon would be here.

Things I would add:
Fact or Fiction It can be big card advantage depending on how badly your opponent doesnt want you to get a specific card. Or you can dig through your deck for what you need 5 cards down.
Ancestral Memories I love this card as it digs deep in your deck and lets you pull out 2 cards into hand.
Opportunity is a big card draw spell with instant speed. A nice perk.
Impulse is another good one for searching for a specific card and it is low mana cost.
Sundering Titan if you are looking to lockdown all the lands of your opponent then consider this buddy. It might be a bit rough as you are running 3 colors yourself and might have to loose some yourself.
Teferi's Moat seems better to me than the magus as enchants are usually harder to destroy. Granted you have to pick a color for it it usually seems to work well.
Blazing Archon Outright seems better to me than the Angelic Arbiter you are currently using.
MORE WRATH EFFECTS. I am concerned about the fact that you dont have much control effects. I would at the least add 2-3 more effects just so you will more consistantly draw them. Most of your creatures wont be online until late game so you could easily use wraths early on.
Detritivore He wont be as good vs mono colored decks but tons of decks run 8-10 nonbasic lands even in mono colored decks.
Myojin of Infinite Rage He is an indestructable 7/4 creature who can at will destroy all lands at will.


Some things I would keep in mind is that running artifact mana accel seems common enough. If nobody else in your playgroup is running much of it you might not need to worry much about it but you could easily splash some hate for it to lock them down further in your deck. Return to Dust is a good solution to hit some of your opponents though as it can hit 2 targets and remove them from the game.