A couple people said just to build 20-30 Cobalts as the early game fleet, but I've also heard several people say that Cobalt's suck
I personally prefer Corvettes as they move faster and are better against siege frigates, which allows for faster expansion, but the LF+Corvette combo is definitely a great early game starting fleet, since they counter each others main weaknesses. Cobalts could arguably be the worse LF, since the Disciple vessel is a bit more efficient and the Skirmisher has that useful self repair ability (though at the expense of firepower, and I don't think many Vasari players really use this ship a lot), but there really isn't a huge gab between them. Cobalts sucked a lot more before Rebellion since Long Range Frigates did not have a good counter.
I'll put the Akkan and Marza together with mostly Javelis, Corvettes, Garda's, along with a handful of Krosov (to siege with Marza), Hoshiko (for repair), and Percheron (for fighter/bomber support) so that once the Marza's done destroying the planet with planet raze, the Akkan can colonize it.
Akkan followed by a Marza is certainly a good cap order. For the frigates though Corvettes and Hoshikos are my only must have ships for my early/mid game fleet. Javelis are great at killing capitalships and light frigates, and can double as a non-Vasari starbase counter with the Akkan's Targeting uplink ability at higher levels, and the Garda's will absolutely destroy corvettes, but if your enemy doesn't have a lot of these ships I wouldn't rush to get them. As for the Krosovs, I sometimes go entire games without getting Siege frigates. They should usually only be built if you already clearly won or your opponent has a lot of planets without any defenses, in which they make decent harassers. As annoying as it is to have your capitalships out of action just bombing planets, its usually better than sinking money and fleet supply into fairly expensive ships that are near useless in a fight.
usually a Sova but those get destroyed way too easily... Regarding the Sova Carrier, should I keep it back away from the fight like you should with light carriers like the Percheron?
I actually find the Sova to be a very competent brawler, especially early game. Its base weapon damage is pretty pathetic but thanks to its missile batteries and lots of strike craft, I wouldn't be surprised if it out DPSed the Kol, and before flak frigates and fighters are deployed 3 squads of bombers are extremely useful against enemy capitalships or taking out militia heavy cruisers. Late game it is indeed a lot less useful, and here you should use it more as a carrier, sending out fighters and using embargo from out of enemy range if they have a large fleet.
Just some trivia, before Corvettes Sova rushing was actually the main TEC strategy, as getting Embargo on your opponents homeworld is so devastating economically without many other planets, and if you happen to be very close to an enemy's homeworld I'd try picking it as your first or second (but get it built ASAP) capitalship. Try it out on point blank just for fun, great practice for rush strategies and you can kill even the highest level AIs if done properly.
But seeing it get destroyed after telling it to retreat with nearly 2,000 hull left at level 4-5 several times makes me wonder if that's such a good idea.
When the fleets get large enough in Sins, this can happen to almost any capitalship (high level Kortul and Corsev being the main exceptions). If 800-2000 fleet supply worth of ships focus fire on a single 50 fleet supply capitalship there is very little you can do to save that cap. The AI fortunately rarely uses focus fire very well though, so its less of an issue in single player, but if your caps are indeed being destroyed very quickly you might want to keep them all on the edge of the fight and only commit them when their special abilities will do the most good.
Also, your enemies don't have phase jump inhibitors do they? If you tried to retreat from a planet with one of those, yeah the chances of your cap ships dying go up dramatically.
One last thing, I never really have any problems against 1 AI in normal or hard, but against 2 AI's even on normal I start to see those problems; should I practice with 2 on 2 battles with one of the AI's as my ally? Would that be harder than 1 on 1 battles but a little easier than 2 on 1, allowing me to ease into 2 on 1 battles? Because I'm starting to wonder whether if the reason that I'm losing is that I end up spending too much time focusing on fighting or expanding into 1 of the AI's territory and allowing the other to become too powerful.
Typically in a 2v1 situation against the AI, you need to read the map well and find a good chokepoint or two that can be used to totally cut off one AI and fortify them really well so you can focus most of your attention on destroying the other. The AI is generally not very good at attacking heavily fortified planets, so a fully upgraded starbase supported by 3-5 repair bays can devestate most early-mid game and possibly late game AI fleets with little difficulty. If its a TEC AI it occasionally can overpower this with obcene numbers of Ogrov torpedo cruisers, but against most AI less than unfair that should give you enough time to defeat one of the AIs, giving you more planets and a large economy to kill the other.
normal AI is lame after I actually got beaten by it twice in a row
Sounds like you have a decent understanding of the game, I would guess your main problem is either execution, mainly taking too long (the normal AI may become a lot harder if you leave it alone long enough to develop), or misspending resources on things you don't need (most new players, especially from the 4X genres, spend way too much on stat increasing research early on when they should be building ships and expanding).
