My analysis and suggestions:
Buildings:
Tavern: Need change the Happiness to something else.
Theatre: Remove the specialist. Add some bonus to be like Museum and Broadcast Tower, maybe "+1 Culture per 6 Citzens" and no base culture. Two GWs would be cool but as phantomaxl said, probably will make Globe Theathre weaker. (Edit: I think an extra slot for GW is better than a Writer Specialist because it fits better in CBP)
Gallery: Choose one as base: +2 Culture or +10% Culture in city. Take from Museum: +33% GArtists rate in city and +1 Gold to All Artists Guilds. (What about putting this one at guilds?)
Manor: Ok, but looks mere.
Salon / Academy: Academy will probably allways be stronger in CPB because (if I remebered right) it's the only "normal" building that gives bonus percent science. (however if you'll build Smithsonian Institute this is different). (I have a weird idea, if the Salon gives +25% G Artists, Writers and Musicians and the Academy +25% G Scientists, Merchants and Engineers?)
Weigh House: Looks ok.
Gunsmith: Maybe could give more bonus (20-30%) to Production of Gunpowders since it's the only thing that it gives or add some other bonus.
Cloth Mill: +1-2 Gold from Plantations looks cool.
Bastion: I think the "Wall-line" needs a little bit of a remake.
Drydock: It should require something instead of Seaport because it's in an adjacent Tech.
National Wonders:
Tower of Buddhist Incense: Fix it as a CBP NW.
Wonders:
Gripsholm Castle: Probably just remove the Great Artist point. Maybe add some free building.
Topkapi Palace: Ok.
Versailles: Ok, maybe could give a free Manor.
Wat Phra Kaew: I don't know if it's me but this +2 Science from religious buildings looks too high.
Torre Del Oro: Looks ok.
Smithsonian Institute: What about if it gives GW of Writing instead? Maybe 3 and a free GWriter.
Kronborg: What about a free Admiral? (I think there aren't a free GAdmiral wonder).
Fasil Ghebbi: Looks ok.
Policies:
Rationalism requires Enlightenment but Imperialism and Industry requires Renaissance.
Cultural-GWs Buildings line idea:
Amphitheatre, Gallery and Opera House require Monument.
Theatre require Amphitheatre, Museum require Gallery, Broadcast Tower require Opera House. Hermitage require Museum (or maybe requires Amphitheatre, Gallery and Opera House).
Techs:
What about removing one tech from Renaissance and one from Enlightenment? this way is easier to balance (more like CBP), both of them will be 9 techs eras and then we don't have techs that looks whortless like Manufacturing, Warships and Armour Plating. Could do the same for Industrial Era.