I've played two games with the JCityLimit mod now, both with the original city limits (1/3/5/7/9/11/13). Lost to a Space Colony Victory in the first game, but won a Cultural Victory in the second game (both at Noble Level).
Got lucky in the second game and had Copper resource in city limits of capitol. Built 5 Axemen and 3 Spearmen and captured the Mali capitol, eliminating them in the Ancient Era. Nice to have that one city capture overage. When I captured it, Timbuktu was the holy city for Hinduism and Judaism

and had The Great Wall
IMO, being limited to one city in the Ancient Era has the potential to make this a very difficult mod to play with. If you don't get copper or horses within the city limits of your capitol, you better hope that your next door neighbor doesn't either!
Also, I think that with these original city limit restrictions, you've got almost no chance for a Domination Victory

You might be able to make all your cities high population cities and come close to the population requirement for domination, but I don't believe you would ever get close to the land area requirement on a standard size world
Another minor problem I encountered in the second game; I got two quests where I had to build 7 Libraries and 7 Colosseums before the Renaissance Era, but couldn't complete those quests due to the city limit restrictions. Not that big a deal in the long run, but would have been nice to have a chance to complete those quests.
So I guess my question is... have you ever considered adjusting the city limits?
I've been working on a revised version of the mod where I set the city limits for the eras at 2/4/7/10/14/19/25. I've also set the city limits for barbarians to 6/5/4/3/2/1/0. IMO, barbarian cities should occur less frequently as the game world moves toward the Future Era. I've also added in restrictions so that nobody can build a city on Flood Plains or Jungle tiles. So far, it seems to be playing OK, but I haven't played a complete game from start to finish with my revised numbers yet.
Any opinions/comments/constructive feedback on my revised city limits?