What I've noticed the last several games is that around the end of Renaissance or beginning of Industrial age I end up at odds with most civs for seemingly no reason. And it seems almost impossible to revert their opinions without caving to all their demands for the next 1-200 years. Spreading my religion to the whole world = bad relations, being close to another civ = bad relations, building wonders = bad relations, asking them to stop spying = bad relations. And very few things give good relations, open borders which is hard to sign with half of the civs. At 190 income 2 of the civs require me to give them 100+ gpt to sign it. Or if you happen to be friendly with someone they tend to ask for 1/6 of your income just because (not sure if that incurs a penalty). And lots of other stuff like that. So people how do you manage you AI relations ?!?