and the beautiful combat rendering of GC2 with MOO3's map-based tactical combat?

Synopsis of tactical combat in MOO3:
build only missile frigates with a couple sensor heavy ships
detect enemy first
fire off every single missile immediately
flee if enemy is not destroyed
(after the major patch the AI would do this too, though most of the time it would just flee)

MOO3 is the turn based strategy equivalent of "Don't Do What Johnny Don't Does", its probably the main reason I welcomed non tactical combat.

Attacker should have the initiative unless combat takes place in a square that is in the defender's zone of influence, then I would give initiative to the defender.

Home space advantage. Good idea.

Yeah MOO III is a pretty crappy game to be comparing to GalCiv II for anything. And tactical combat would just be another stab at the AI. The more the AI has to contend with, the less it appears to be a quality AI. This AI is pretty good and non-tactical battles is the way to go for it. No exploiting the AI with tactical exploits. It's all in what you build and how well you build it. Perfect for an AI based on mathematics. I do hope they never implement any tactical battle feature in future editions.

Haha if the defender has the advantage it will be like: "comeon attack me!" "no, you attack me!!!"

Yeah, we wouldn't know for sure unless we tried it, but I think defender advantage (or even "home space" advantage) would just encourage turtling, and slow down the game.

Both the player and the AI would need heavier invasion fleets, which take longer to build. I like the pace of the current design. I like having to keep on my toes. If I screw up and let the enemy hit me first, then I'm not defending very well.... OR, it means I've adopted a static strategy where I'm beefing up the defensive value of my ships to absorb the first strike, instead of beefing up their speed so I can control the battlefield.

Surely, the very word initiative comes from the word initiate. So the initiator of the attack gets the initiative strike. As there is no "digging in" in space, I dont see how a defender could develop some inherent defensive ability to countermand this other than sensor range, movement rate and maneuvrability, and longer range weapons. The first 2 are in to some degree so use those to ensure that you have the initiative by attacking incoming ships.