@elhanna: Razing cities makes AIs dislike you, but it doesn't affect your rep.
RoP rape would make further RoP impossible, but it wouldn't affect GPT deals. And in the game I didn't do that - I always made sure my units were outside of enemy's territory before I declared war. This way even if you had RoP it wouldn't matter (and on the other hand even if you do not have RoP, it's RoP rape if you have units in AI's territory anyway).
iron - I may have traded it at some point, but when Russia had it I was not doing that so it was not a problem.