Great mod so far, I really enjoy not seeing all the resources right from the start and also that the concept of beelining has been reduced to prioritizing techs in the eras.
Are you planning to include more changes to the leaders UAs, UUs and UBs (although the changes to America were mostly done to fix an exploit)? One inspiration could be the Communitas mod project were some UBs give instant boosts (f.e. paper maker gives additional instant science boost -> real fun building great library) or have early specialist slots to earn great people from the start (f.e. greek odeon, amphiteheater replacement, new UB replacing Companion Cavalry; has writer Specialist spot also instant culture boost ... yeehaw). Also the leaders start with different units which makes early gameplay much more different (f.e. Rome and Carthage each start with a Ship -> early coastline exploration; leaders with ancient era UUs start with one of them -> Persia-Immortal Greece-Hoplite, which turned out to be imba if you can upgrade to early Pikemen with ancient ruin and kill the world).
Another thing communitas does which seemed very reasonable was sorting religious beliefs differently. Primarily all religious buildings are moved to reformation belief and some more faith building options are added (like jesuit education for military/mercantile/cultural buildings). All beliefs that directly modify religion spreading (interfaith dialogue, missionary zeal, heathen conversion etc) are moved into enhancer while founder and pantheon govern resources (faith, happiness & culture per tile). All city-state related beliefs as well as " "bonus" per followers in other nations" are relocated to follower.
The benefits of that system would be to prevent the AI from taking up all the buildings without making sense (two opposing building types in one religion). Also in my current Arabia game religion appears to be somewhat unbalanced (Religion: Desert Folklore, Interfaith Dialogue, Mosques, Reliquary, To the Glory of God -> trying to win cultural; Holy city focused on population growth for many specialists and religious pressure, many farms (flood plains thank god) and harvest festival + Grand Temple, Great Mosque of Djenne -> i´ll flood the world with missionaries (even faster by pumping out great works, or music tours through reliquary once in a while GM for Gold or GE for wonders) which boost my science output while buffing my tourism output through shared religion->seems a little bit like overkill to me). With the communitas system I would have to let "reliquary" and to "the glory of god" (is enhacer there) go for the given example, which would turn out less imba I guess. Because the system would only allow civs which complete piety (religious powerplayers so to say) it would also be more immersive for AI Interaction.
Also steam didn´t download and certain conditions render cities invisible.
Wall of text, yeah.
edit: also harvest seems OP since it skyrockets the population growth of the city it is build in, I think it should rather give a strait happiness bonus in the basic effect (like it does already) and deal with unhapiness per citizen in it´s complex effect (maybe like full effect in city which it is built in and half effect in all other cities -> usefull for tall and wide) since festivals don´t produce food themselves but make people happy about having a feast.