Well, this is my first post on this site, and I'll admit I haven't been playing for that long, however, looking over everything, I've already made a few observations against the A.I.
Well, to start, I wanted to praise the new defenses of the stationary turrets. Having the short range rockets, and the longer range cannon makes it so much more useful against pirates and siege ships, basically making them much more useful. I still think that the main weapon should still have a bit longer range, but that's a relatively minor change, and is quite unnecessary.
Starbases are quite interesting, I find. A few complaints though, is that their weapon range is pathetically bad I do find it entertaining when pirates are stupid enough to go after trade ships near the station, but most commonly, the station is ignored by just about everybody. Their range is way too short, especially the "extreme long range" rockets, which I find laughable.However, the space stations should get some flak guns. Not enough to be completely crushing to enemy fighters and bombers, but enough to make a sound impact on massive bomber waves.
The upgrades, for the most part, are quite good. A few small tweaks should occur though. I think that stations should have small popuations, like asteroids. Make it a part of the trade ship or the auxllary government addition, but I think a small tax revenue would make the stations more realistic, considering their huge size. People have already brought up auxllary government upgrades not working, and I decided not to bring up a moot point (even though I brought up weapon ranges...heh).
Something I read in another thread, and I believe would make a powerful addition, is that there should be salvage and refugee ships. If not in this expansion, another expansion. This should also have some effects on the diplomacy in the game.
Refugee ships should be easy. If your fleet conquers an enemy planet, not everybody should be killed, but instead, the planet has civilian refugee ships, all of which are completely harmless to you, launch and make a quick dash towards a jumpgate to their nearest allied world. Now, your fleet could basically destroy them all, but that would basically remove any chance of a peace agreement or any agreement at all, even a cease fire, and if one of your planet falls to them, they will show no mercy either. However, destroying them would give you credits, in the form of salvage. If you let them go, the enemy would gain a small population boost on the arrival planet (it can be either increased max pop, or just increased population growth) and a small boost of credits.
Salvage, however, is the main idea. Both in dealing with space junk, and ship/station/structure ruins, you can see debris appear on the map floating around. Now, salvage ships, I think, can be basically be a new ship, much like the Colony ship or an add on to a colony ship, or a completely seperate ship itself. These will "salvage" ruins from battlefields, giving you some metal and crystal, and sometimes a small credit boost when you find POWs or survivors from your ships (POWs being a slave work detail, giving you a small credit boost, or gifts from families of survivors that you find. ) Now, when just dealing with space junk, it should be salvage ships slowly working in the area forever, granting a metal or crystal, or both, production. Bascially they're neutral extractors, except you build them, and that they can be destroyed.
Sheesh, totally forgot. TEC mines, I think, are the best form of mines in the game, though I think there are some delayed explosions, which annoys me. The timing should be better off, but I believe they work quite well, and they look cool