There is a positive and negative number system that does in a sense affect what the AI thinks of you. It is hidden behind one of the diplomacy screens. Compare with Civ IV where I could mouse over the nations on the right of screen and have that information displayed for me. I’d like for that information to be made more obvious. There doesn’t appear to be much in the degradation of negative score though - once a warmonger, always a warmonger really. I miss the simple elegance of the Civ IV diplomacy system.
Also another complaint with the new expansion is emergencies. A fine idea in theory but the systems don’t support it. The last time I saw combat in my Nubian game was to liberate a city state from Scythia. That was fine, I could actually do that one, and the pot of 18,000 gold (!!) was all too tempting. So I signed up. So did Mapuche. I did the hard work, Mapuche offered nothing and we split the pot, 9,000 gold each. It is a system that is too basic. Compare with the projects from previous iterations where the game would reward the nation that contributed the most. They seem to have forgotten that bit.
For 9000 gold, I built a couple of buildings. Gold doesn’t go far in this game.