Hello all.
I just got Sins about a week ago and have been enjoying it immensely. I've only played one full game on a small random map against the ai on easy. Now I'm on the Doppelgangers map in an FFA, where I'm Vasari, and the others are Vasari, Advent, and Advent. Here's a screenshot with my current position after about 4 hours of play.

I've killed the pirate base there and inhabited it for a while before a huge enemy fleet came and drove me out. I figured it wasn't worth trying to protect. Now I'm just wondering how to move on from this point. I just sent about half of my total fleet to one of the other star systems and took over one of the ice planets there, with the goal of increasing my crystal rate, but it wasn't long before the enemy forces overwhelmed mine and I was forced to retreat.
I'm slowly building my fleet back up to it's full capacity (I think right now I'm at the point where its upkeep uses like 47% of my resources. I'm afraid to go any higher than that since my crystal level is so low. It's only increasing at 1.3 or 1.4 per second.) My fleets mostly consist of Kanrak Assailants, Skarovas Enforcers, Stilakus Subverters, and Serevun Overseers. I think I'm going to limit my use of the Subverters and Overseers and make a little more of the the Junsurak Sentinels, as I was blown away by the number of fighters thrown at me in the other star system. I could use some advice as to what kind of ships counter other ships. I've been having particular trouble against the Advent's purge vessels.
Also, what do you guys recommend as far as diplomacy? As of yet, I've just ignored every mission that my enemies offer, because every time I get their disposition slider at about 30-50 percent, one of my ships will kill one of theirs and it's all the way back to 0 again.
I'll appreciate any comments or suggestions anyone has to offer and can provide more information if needed. 