I tried a Roman game. I got to conquer 2 city-states close by Rome, but then the negative resting point thing started to happen. It's gonna be hard to conquer the Italian peninsula without being shunned by the rest of the world.
I know the Romans didn't conquered the Italian peninsula in theory but rather set up alliances with the different cities, in which the individual city (junior partner) provided tributes and manpower to Rome (senior partner) and this setup only changed after the Social war, where the Italic cities was annexed and its inhabitants was granted citizenships.
Some bugs, missing contents and other technical issues.
-I didn't encountered any crashes while playing...
-I noticed that when I was conquering my first city state I had like 4 melee units next to his city and he had like 3 units that was just fortified and didn't do nothing while my units easily conquered his city taking only 1 hp damages while dealing 30 each turn. This kind of AI behavior makes sense in the normal game because the cities can bombard and inflict damages on attacking melee units, so normally it would makes sense for the defender to fortify its units, wait for the city to inflict damage on the attacking units, and then attack with your defending units, at least thats how I think the AI is sort of programmed to behave.
I have some thoughts on this:
-Revert it back to the normal game system.
-Take some inspiration from the "American Civil War" scenario from BNW.
-Keep it as it is.
-Develop some defensive buildings that will increase city HP and strength(damage returned to melee units).
Some buildings could be:
Palisade wall. adds HP.
Archer towers. req. Palisade wall. adds strength.
Stone wall. req. Palisade wall. adds HP
Burning Oil(you know the kind you pour on the enemy when he tries to smash open the gate). req. Stone wall. adds strength
-It seemed that I couldn't build the "get 5 slaves in a conquered city building" (can't remember the name). This was before the version where you added the Bath, Flavian amphitheater, gladiator, tax collector and so on...
I tried waiting until the puppet couldn't build more buildings and just stop building anything altogether, then I annexed and still no slave building.
Some flavor comments:
-Maybe add some more city states, representing smaller tribes, in Iberia, Gaul and Britain. I know your idea is have to give the barbarian civs a lot of space to grow fat in, so they eventually will become a big threat to Rome.
-Maybe give some of the bigger civilized non-Roman civs some more cities to sort of push them in their historical direction, like you did with Carthage.
I wouldn't mind seeing the Nile delta with cities in it.
-Maybe add the Cisalpine Gauls as a civ and give them that gallic guy, who raided Rome when it was still a small insignificant city, as leader, Brennus or something.
-Maybe make northern africa (modern Tunisia and Libya) more fertile, in ancient times it was known as Rome's bread basket. It was only later in time that overproducing and decertification turned it in to the more arid environment there is today.
Finally, congratulation on a fine job so far and I know its far from finished and there is much work to do and some of my complaints/comments might already be fixed or you already have something similar in mind.