Elkad and Niklas, now that CH is gone, I have a proposition.
You treat the AI as though it was still my ally, that is, declare war on it if a war starts between us (because it wont join the fight on its own), and remain at peace if no war starts. Also no open borders.
Then I will treat it as though it was still my ally too, as opposed to quickly gaining a bunch of free cities, which would benefit me more with my tech than having a clueless AI run around with rifles.