A few newbie questions.

[llamabeast]

I would say that you could do very well out of trading items and information if you made an effort with it, but you would still have to have some base of military strength. Your capital is just too juicy a target for other players to leave it alone if you can't defend yourself.

In Galactic Civilizations II I once had an excellent game playing as "The Foundation" (based on Asimov's book). I colonized no planets and didn't build any military until a long way into the game, but concentrated on playing the nations off against each other, trading techs and also doing a lot of research myself. I won. It was awesome.