With my usual caveat that I haven't played C3C in ages and can't currently get it to run:
I never agreed to RoPs. I just can't stand having foreign troops on my soil. And the pointy stick works pretty well for both research and banking.I rarely get involved in most forms of diplomatic agreements beyond basic peace treaties and RoPs. In a typical game I will have 6–8 resources and sometimes hundreds of gpt flying back and forth between me and the other civs, and war is just bad for business.
I'm not convinced that the player's reputation ever recovers from anything. Break an alliance or a long-term deal (for resources or gpt), and you just can't get the AI to agree to it ever again.....Basically, pulling out of that alliance early is how I lost the game, because my reputation never recovered.....
Might I suggest a trip down into the Succession Games forum. Years ago, I put together an Archive of Training Day Games. I haven't updated it in years, but the TDGs are full of good discussions about what we were doing and why. There may even be some saves you could download to look at.....Anyway, question: what are the mechanics of what make, say, Monarch more difficult than Regent? I have 2 wins, 3 losses so far (going for the Mayans next - much more fun than Rome anyway).