They gang up on the strongest empire. Every AI you have some kind of cease fire/peace treaty with will go bug another AI, so that's 2 out of the picture. I generally keep the AIs on one side of me with alliances so I can dedicate to fighting on one front without worrying about my back-end planets.

And I pretty much exclusively play 9 Insane FFA (except Entrenchment beta which has some performance issues to make it not go so well )

You try to be quick. Don't scout out too far in the beginning, let the AIs find you first (they don't give you missions until you've "met" them by seeing one of their ships) to give yourself time in the beginning to build up and get your economy going. Don't over-expand either, as the kill missions only start coming if there's a target within 2 jumps of any of your planets. If you do it right, you can get a cease fire with just giving resources. With the timer on those, I usually get 2-3 closest AIs in a cease fire, and then for the third round of missions I just see who's easiest to please. Often 2 of your friendly AIs will ask you to attack the same target (might be your third partner). Kind of easy in that case

You don't have to do every mission, either, as the time goes on. They won't break a cease fire until your happiness drops below 35% or they run out of everyone else to fight. If you get a few successful missions in, you can easily fail 1 or 2 (so an hour or so) before you need to worry.

The AI may have an easier time allying with themselves, but they also cheat with you a bit since they're very loyal once the treaty is made. And very predictable

Yeah, they tend to gang up on the human empire and form non aggression treaties extremely fast.  Even simple games get hard when you are simultaneously attacked by different empires on different fronts.  Selecting the teams so that they are locked at the beginning makes the game far, far easier.  You can still unlock the achievements this way.  Its how I did it.  Playing on multiple star system maps also can buy you some time in the beginning because most empires will not be doing much interstellar travel before you have a functional empire.

Sins is pretty forgiving when you turtle as well.  Its usually death in most 4x games in that you usually need to be expanding on some front. The AI will strike areas they see as weak, so it is advisable that you dont park your defense fleet near the front.  Instead park it a jump away and the AI will continually underestimate your fleet pressence if you kill all the scouts within the first system.  Hangers and jump inhibitors help a great deal in closing down the AI info on your empire.

I dont bother with diplomacy at all in the beginning. I turtle, build a second 'invasion fleet' and then stick to hitting one faction.  This incidently causes the remaining factions to like you more just by fufilling the missions by chance.  Vasari really reward patients as those phase jump gates make moving one defense fleet pretty easy among a solar system.

Ah, didn't know about this. It might help in battles and large empire managing

Seems almost sacrilegist to change game speed. Thats what save and pause is for. This is and I hope not ever Command and Conquer.

agreed.

I didn't know they were even there.

still, let's burn him to be sure.

Can I borrow this for a second? I think the fox could use a tan.

Which is why we burn it off, first!

You aren't safe there, either.

With the TEC, it's actually pretty easy right now. Just get 2 Marzas, a Dunov or two to keep their shields up and you're good to go. Just wait for the enemy fleet to all be in range of the Marzas' Missile Barrage ultimate, and let it loose. The AI is pretty bad at interrupting them, so a full-lasting barrage from both is pretty much guaranteed to knock out all the smaller ships.

That's a bit too cheap for my liking, though, so I usually use one at most, supported by a pair of Dunovs (one to recharge shields, the other for EMP blast/fighter suck and recharge shields in a pinch). A good helping of Hoshikos (about 1 Hoshiko per 5 combat ships) and a few Cielos for target uplink (10ish or so, they don't get targetted too much). Your capital ships and heavy cruisers will draw the most fire, and the Hoshikos can keep them up quite well along with the Dunov's shield recharge for the caps. Your LRMs will be very brittle and die fast to enemy heavy cruisers, so try to take out those first. Zap enemy capitals antimatter with one (or both) of your Dunovs early and it'll get rid of a lot of their annoying abilities. Rank 3 of the EMP blast drains 450 AM, so 2 zaps will deplete pretty much anything.