Figured I'd finally make this thread as I got around to trying the full thing out(I think).
All I've done so far is making a full installation from steam, running it alongside with the full CPP. I'll just list the things that I see clearly not working out properly, or things that are clearly under/over-tuned.
First of all, forges(which are a staple building in CPP and a requirement for workshop, factory and windmill are not buildable without a workable source of iron/copper in range.
EDIT: Pioneers and Colonists seems to bypass this problem and start with a forge, guess delayed expansion pays off.
EDIT: Turns out I was wrong about windmills, they are buildable everywhere (even though the building itself claims it can't be built on hills) it also has really weird yields, including +10% food.
Second, a lot of the pantheons added are extremely underpowered compared to the CPP ones (this isn't exactly a problem as you can just ignore them, but they should probably be dropped if only to avoid the AI accidentally picking them)
One of the mods, no idea which one seems to pretty much break the EUI top-bar, which is kinda sad to me because I like that bar
EDIT: Turns out I managed to miss the EUI installation step on one of the mods, fixed it now. Instead there is some weirdness where your current 'piety' level doesn't really show up, it tells you how many turns you have left until you drop/gain a level, which is a lot less useful than just seeing the number you're on, at least in my opinion.
The Forum Magnum, requires liberty (I was able to build with with progress, no idea if it is buildable without it). CPP still adds the Parthenon as a progress wonder meaning if the Forum is policy-tree locked, progress have two wonders available to them now.
The top right industry-policy is replaced by Mercenary army (reducing merc costs by 20%), that is a lot worse than the current top right industry policy.
The top left Imperialism policy, "Martial Law" gives you 15% cheaper mercenaries while still having all its old effects (cheaper upgrade-costs and more productions in puppets)
One of the mods seems to break the economic view, I can only see my capital on the list, and most of the yields are all over the place.
The monopolies window seems a bit bugged as well, the only resource I can see on the monopoly-list is Ginger (which I don't have a monopoly of) while Saffron and Salt (which I have monopolies of) won't show up.
The foreign and potential monopoly doesn't seem to be working either.
I'm also able to build all land-units with faith (but that might be intended
I have access to two completely different buildings called Chancery, one with dignitary slots and one with civil servants.
The mod seems to overwrite Gazebo's auto-assign thing for great works, the buttons are missing.
The monastery policy in Piety does nothing, as you're already using the monastery as a normal building. (it doesn't even give you the ability to purchase your normal monasteries with faith
)
Cologne Cathedral doesn't have a gold-rush cost.
Not exactly a bug, but I get a pop-up asking me to switch my name to Isabella the Zealot every turn, it gets pretty annoying after a while (maybe there should be a cooldown on it or something)
This is all I have so far, but I'll keep digging.
All I've done so far is making a full installation from steam, running it alongside with the full CPP. I'll just list the things that I see clearly not working out properly, or things that are clearly under/over-tuned.
First of all, forges(which are a staple building in CPP and a requirement for workshop, factory and windmill are not buildable without a workable source of iron/copper in range.
EDIT: Pioneers and Colonists seems to bypass this problem and start with a forge, guess delayed expansion pays off.
EDIT: Turns out I was wrong about windmills, they are buildable everywhere (even though the building itself claims it can't be built on hills) it also has really weird yields, including +10% food.
Second, a lot of the pantheons added are extremely underpowered compared to the CPP ones (this isn't exactly a problem as you can just ignore them, but they should probably be dropped if only to avoid the AI accidentally picking them)
One of the mods, no idea which one seems to pretty much break the EUI top-bar, which is kinda sad to me because I like that bar

EDIT: Turns out I managed to miss the EUI installation step on one of the mods, fixed it now. Instead there is some weirdness where your current 'piety' level doesn't really show up, it tells you how many turns you have left until you drop/gain a level, which is a lot less useful than just seeing the number you're on, at least in my opinion.
The Forum Magnum, requires liberty (I was able to build with with progress, no idea if it is buildable without it). CPP still adds the Parthenon as a progress wonder meaning if the Forum is policy-tree locked, progress have two wonders available to them now.
The top right industry-policy is replaced by Mercenary army (reducing merc costs by 20%), that is a lot worse than the current top right industry policy.
The top left Imperialism policy, "Martial Law" gives you 15% cheaper mercenaries while still having all its old effects (cheaper upgrade-costs and more productions in puppets)
One of the mods seems to break the economic view, I can only see my capital on the list, and most of the yields are all over the place.
The monopolies window seems a bit bugged as well, the only resource I can see on the monopoly-list is Ginger (which I don't have a monopoly of) while Saffron and Salt (which I have monopolies of) won't show up.
The foreign and potential monopoly doesn't seem to be working either.
I'm also able to build all land-units with faith (but that might be intended

I have access to two completely different buildings called Chancery, one with dignitary slots and one with civil servants.
The mod seems to overwrite Gazebo's auto-assign thing for great works, the buttons are missing.
The monastery policy in Piety does nothing, as you're already using the monastery as a normal building. (it doesn't even give you the ability to purchase your normal monasteries with faith

Cologne Cathedral doesn't have a gold-rush cost.
Not exactly a bug, but I get a pop-up asking me to switch my name to Isabella the Zealot every turn, it gets pretty annoying after a while (maybe there should be a cooldown on it or something)
This is all I have so far, but I'll keep digging.