Yeah my actual game is like that.

At challenging level, huge map, 9 civ, 4 civilization have gone before I was able to be near the greatest power (drengin empire, korx)

But that's how I like it hehe.

My strategy isn't perfect, but it works okay most of the time:
1. Building things is cheaper than buying things.
2. Basic factories cost less than colony ships. It's something like 1000bc to 450bc
3. In order to get ahead, you must purchase items.

1. Purchase a bunch of factories on my homeworld.
2. Build colony ships quickly (Three turns)
3. Colonize planets, good ones first, lesser later if the other races have not colonized them.
4. Use the money I saved from not buying colony ships to support the new colonies until they can support themselves.

As I stated, this strategy does have flaws. I tend to keep military spending way down, and social and research spending way up. Result: I have no military.
Problem: Other races look at me and think, "Hey, there is a land flowing with milk and honey and there is no one defending it! Let's jack 'em!" Result: I'm often at war.

War isn't always a bad thing, though. I often switch from social spending to military spending. I build up navy quickly, and the opposition just lost some of their worlds, hopefully the good ones.
Also, since I usually have a lacking navy, I have learned that well positioned and defended military starbases are invaluable.


I think that's all I have to say for now.