I've done some (not much, but some) gameplay and I've caught a couple of issues which I'll get to below, but the majority of your new material is flawless. Much of it far outshines some of the original content, and many civs are significantly improved already, even if the new material isn't perfectly balanced yet. Firaxis and Co have obviously made some (not much, but some) pretty odd and inconsistent choices in the game and this mod is already fleshing things out (I'm particularly thinking about Sweden and the Ottomans, but there are others. I've been mainly focused on the buildings side of the mod, as I'm an unenthusiastic warmonger at best. Anyway, a few quick notes, I'll post some more soon:
America's Saloon isn't working fully. I haven't been playing as the USA yet but I've noticed that the gold on hills is not materialising, I can't say if it's working on furs because I have yet to see the Americans with furs. This aside, I'm not convinced that this early in the game is right for an American unique, I know it's very hard to make the late game civs compelling early on but sometimes it just can't be done and I think America is a case in point. Perhaps you could move the Saloon to the Bank slot, or come at America with a different building. I saw Skyscrapers previously mentioned, perhaps playing around with that would be better? A combination of boosts in population / tourism / bonuses on Great Scientists, Engineers and Merchants, would be pretty sexy.
Similarly the French Salon is too early, although it's working perfectly and is a great creation. Perhaps pushing it back to a Windmill replacement, like the Coffee House? Or maybe even revamp it a little as a French replacement for the Hermitage.
The German Rathaus is a monster with it's 25% production boost, to the point where it's actually quite terrifying being neighbours with Germany. (Perhaps that's the point?) Maybe bringing it in line with the Workshop would be friendlier (10%) but when building it in Occupied cities a higher amount would be fine, even the full 25%?
Last one for now, the Swedish Stave Church, though it's working fine, it isn't very thrilling. I think if Sweden had been made differently it would be perfect, but the Swedes are such a weird civ, with their diplomacy UA and warmonger units. The Stave should tie in with their UA, so adding a Great Person production boost, or +1 faith per friendly CS would really help Sweden keep up with it's rivals.
I'll give some more feedback soon, but maybe someone else would be better to look at the units you've added, because, as I've already said, I'm a peaceful kind of fellow.