I'm going through my first playthrough (yeah I'm slow) and I kinda stuck here in the Civilization stage. I was doing fine until I unlocked planes. At this point, the Blue nation went fucking berserk and just slaughtered every single civilization left in the game except mine, since I happen to be trying to stay on their good side for whatever reason. So, now me and the blue nation is all that is left. I have all of the starting continent but Blue has everything else and could easily make me their bitch if they wanted to. All my spice mines are pretty much completely empty so my income is coming in really slow. Besides, every time I'm gain enough money, I always send it as a gift to Blue to up my reputation with them. Either that or they demand it from me. There is no way to take these guys by military or religious means. So, what would be the best way to ally with them and convert them to my side? It's pretty much my only hope. I'm really stuck between a rock and a hard place here.

EDIT: Forgot to mention, as of right now, I'm only at +26 rep with them.

Wow, don't have the game, so I can't help you. But it seems so deep. I really want to play this. 

Aw shit...I seemed to have stopped gaining reputation with Blue from offering gifts. Even gifts of 4,000 sporebucks isn't enough to get me past 60 rep. Does the reputation from gifts cap at +120 because if it does...I'm fucked.

I was in exactly the same situation and got out. I got all the spice mines possible and took one city at a time by religion, I made every city that I obtained military and made sure that they were defensive whilst I crusaded my reigion to other cities. It takes a while but it is possible.

"Wow, don't have the game, so I can't help you. But it seems so deep. I really want to play this. "

Build a crapload of tanks and ATAAAAAAACK!!!!!!!!!!!!!!!!!!