I've only played a little of Galactic Civilizations 2, and I'm getting my ass handed to me in 3. I've tried a few different things, military focus, money focus, tech focus, and even a mix of all; however, I keep running into problems. When I finally get a few planets claimed and star-bases around important resources, almost all the AI start war with me and they have the same tactics. If I keep my ships together and try and fight them, they split them up with troop transports and come from every angle possible. If I split my ships up they come in one force and go straight for my production. If I defend my planets they send all their forces to one and I have no time or warning of which place is attacked.
I also find that the AI ships are impossibly better than mine, even when I focus on ship, weapons, and defense research they can 1 vs 1 any of my ships with a small ship. Any advice would help as I have no idea what I'm doing wrong here.