Some observations that could warrant an update, if anyone code-capable wants to embark on this journey (huge respect if you do; this is definitely not a demand to do anything):
- EE-added buildings have happiness in percentage value still. Just changing it to -1 flat the respective values (Academy, Salon, Menagerie, Manor, Hermitage) works; although the two buildings that 'slightly increase' (Poverty from Cloth Mill and Distress from Tavern) could probably be better off just removed altogether in the new happiness model.
- Tower of Buddhist Incence has a global -10% religious need in all cities, which is probably a bit too good at -1... and you generally build it for the free great person anyway
- Smithsonian Institute also gives percentage reduction to illiteracy; change to flat -1 to all is probably not too strong in this case
- Zoo and Menagerie now both give +1 tourism to jungle/forest and reduce boredom, some differentiation is probably in order; on that note, I've always found Menageries' gold pretty laughable as in most cases it doesn't even cover for its' own maintenance cost
- Gunsmith requiring Iron is now rather forbidding for the effect, given that from next era onward any and all ships(and siege) also now require Iron - might be worth a look
- Bastion/Arsenal lack their respective Empire Needs reduction effect
- Weigh House, unlike other gold-generating buildings, has a maintenance that only makes it positive gold income at 18+ population in a city (earlier if you can work the Merchant, but it's still a bit deep cost for just the Merchant slot essentially)
- the Economics tech boosts 'Colonia', a thing that doesn't exist anymore as a Unique Improvement
- Ship of the Line now has the same CS as Corvette, and since Ironclad is at 60 CS now, could probably bump Ship of the Line up to 45 to make it more worth it.
Those from me staring at the tech tree for a bit; I'm sure I've missed things. I don't think any relevant uniques have changed much.
Policies are trickier to compare; the only one I can directly spot is Mercantilism(in Industry) having the same +100% production to Train Stations/Seaports as the opener.