I agree with you that the min/maxing is a game killer. I did that in GalCiv2 and learned my lesson. It sucks the fun right out of it.
For GalCiv3, I'm taking a different approach. I'm playing it more as an RPG rather than a game that I must win. In fact, my last game was a defeat and while it came as a surprise, it was very refreshing to see that the possibility of losing was really there. Seriously, I didn't know it was even possible for me to lose a game against the AI. I think you're there too.
GalCiv3 isn't as polished as GalCiv2, but if you give it a little leeway, it can be even more fun. Playing for score in GalCiv2 ruined it for me, but I could probably get back into it after all this time and stay away from the min/maxing.
One thing to keep in mind is that Brad wrote the AI in the other GalCivs. He's more of an expert overseer in GalCiv3, so the flavor isn't the same. Brad is without a doubt, the best AI programmer ever to grace the gaming community. And that's an objective fact. His proteges naturally can't match him, but with his guidance, they'll kick some serious ass eventually.
I hope you can resist the min/maxing, even now that you've done some of it. If it's already put a bad taste in your mouth, a hiatus might be in order. With the updates and patches, it becomes a new-ish game every few weeks. After a few months, it might be ready for you.
Personally, I'm having a blast. 