You have control over what your close neighbours are doing to a degree but you have no control over what snowballing civs on the other side of the map are doing.
Again,I love the mod its a great piece of work.
But let's be honest....if you arent commiting to a full DomV or at the very least 90% domV/ScienceV you arent going to win.This is a DomV centric mod plain and simple.
I dont think that is a bad thing but it is what it is.
I don't think you're as good at the game as you think you are. No offense, but if you didn't understand my comment, then you're not getting it.
In order for a civ to win a Cultural victory over you, you have to let them. They have to be influential over YOU. They can be influential with all the other civs except you and they cannot win until they pass you. Which means that you are neglecting your cultural defense. That is 100% your failing. You are letting them win the game. Don't give open borders. Pick different ideologies. Declare war if you have to get rid of the trade routes. Build a cultural defense against their tourism. Snipe tourism wonders. Put military on artifacts. If someone else has won a culture victory it means you did not defend properly against that victory, and the fault lies 100% with you.
You're on emperor difficulty. You have a lot of different avenues for victory, and the only one that's probably not feasible is Diplo. Try harder, it's entirely possible.