Got to play another game as Portugal and noticed a few things:
1. You can now build slave plantations on jungle, which makes sense, but you can also build them on forests. I found that I was able to build super forest plantations on both of Brazil's coffee spawns using slaves.
2. What is the logic behind the extreme variation in commerce yield on plantation resources? I get that because incense spawns on desert it needs some compensation, but, for example, why is tea and tobacco's yield so low? I would think plantation resources could be standardized either as 4c, 1f 2c (i.e. spices), or 2f (i.e. sugar) across the board. Cotton would be the exception but I would suggest either counting the 1p as close enough to 1c that 1p3c is fine, or adding the 1p to a tech like replaceable parts (invention of the cotton gin).
3. Ivory is very weak. Camps are associated with low yields because of an expectation that a forest will remain where one exists but with so much of ivory sitting on a rainforest rather than a forest, improved rainforest ivory modified with a camp changes the yield from unimproved grassland -1f,+2p,+1c. This is comparable to a renaissance era workshop. Early game this is decent but the resource could probably use an extra commerce, after all ivory has historically been highly desired and valuable for craftwork in much the same way gold, silver, and gems were. I would also think the resource belongs in the trading company corporation. I would also suggest for the late game allowing preserve on ivory to add 2 commerce, and to allow preserve to be built on ivory even without rainforest to represent safari tourism.
4. I was getting hit with a -5 stability penalty for out of date civics when I was running republic/capitalism/secularism/representation/mercantilism/naval dominance not long after researching some of those enabling techs. I changed representation to egalitarianism and the penalty vanished. This suggests to me that once you research democracy representation triggers a -5 stability penalty which seems very early for representation to be considered an out of date tech. After all, the enabling tech for representation comes right before the enabling tech for egalitarianism in the tech tree.
5. I agree with you that Naval Dominance should have some economic bonus as naval combat is just less important than land combat in this game and therefore naval domination needs some sort of bonus to balance it out with standing army. However, the custom house building modification seems more appropriate under mercantilism (which also could use a small buff). Instead I would suggest as a possibility +1 production for fishing boats and whaling ships to help coastal cities with little access to production.
6. Holy cow the unhappiness and unhealthiness in the industrial age and beyond is for real. It has made the game a lot more interesting domestically and actually made me consider environmentalism for the first time playing the game. After all free market now also contributes to the happiness/healthiness problem. It's still just not that exciting. Health resolves itself by the time you get access to environmentalism with recycling centers and seven different health generating buildings and it's health that environmentalism primarily interacts with. It's happiness that I would have gone for. I feel like public welfare's university/hospital bonus shouldn't be production but that both buildings should yield one happiness (government sponsored universal healthcare and post-secondary education).
7. Free Market is scary to use now. I'm not sure it needs a buff because it's still tremendously powerful to increase national yield but the happiness problems created are overwhelming. We might benefit from a late game happiness generating building, a counterpart to the supermarket just as a market is the happiness counterpart to the grocer. Civilization 5 uses both a zoo and a stadium which could become available at biology or electricity/industrialism/plastics respectively depending on where exactly you want the building to become available. My choice would be the stadium. While football/soccer is already represented in the game through the Wembley wonder there is a very big difference between local sporting events and a single internationally consumed sporting event. After all, trading for a "hit football event" (which I guess is premier league football games? Hardly wonder worthy from my American perspective, but I digress) can only represent a limited scope of the sporting world broadcast from a single country. A modern stadium represents the gamut running from American football and baseball, Euro league soccer, Indian Cricket, to Aussie rules football. It's just strange that we have sports in the game with Wembley but nothing other than premier league football.
8. Nothing new but when Great Britain gets its Stacks of Redcoats in India it seems to upgrade the vast majority of them with city garrison I and II. Often those stacks fail to take even poorly defended Mughal cities. Perhaps hard coding the promotions will improve an AI Great Britain's chances in India.
The unit upkeep is nothing compared to city maintenance.
