Regarding Happiness:
I played relatively long game on the last patch where I gave the AI larger starting bonuses (difficulty was Immortal).
I was playing as a wide warmonger.
By the Modern Era Happiness was a major concern (I had ~25 Cities).
Even in Cities where I had every building available to me built I would have gotten the full 1 Unhappiness per Citizen if I had not built a lot of Public Works.
Assuming the wiki page for Happiness is up-to-date the main reason was probably that I had a lot of Cities and that I was behind technologically.
I think the current version of Public Works is also too weak, at least if you're going to use it as it was probably intended (I'm assuming the intended use is to build it a few times in every City if you are struggling with Happiness).
The total amount of production you need to invest into Public Works scales quadratically with how many times you've built it, presumably to give it diminishing returns.
However, at the same time you will only start to get any payoff at all once you've built it a lot of times if the needs of your Citizens are much higher than the City Yields (they were in my case).
For example, after annexing Venice and building all relevant buildings the needs of the City were 4 times higher than the City Yields; I didn't even bother to build Public Works in that case because I would have needed to build it at least 7 times in order to get any benefits at all.
Instead I just ignored Public Works in part of my Cities and spammed it in other Cities.
As a result I would get some Cities with the maximum amount of Unhappiness and some Cities with basically no Unhappiness at all; As long as my average Happiness was >50% it was not a problem.
I think Public Works would be in a better spot if it gave you 1 empire-wide Happiness instead of 1 local Happiness.
That would make it so that Public Works always gives you some benefit because the Happiness wouldn't get swallowed up due to a large deficit in City Yields.
4) Navalwise I've been a bit frustrated lately by the binary nature of naval combat. Sometimes I get into these "no win" situations where you cannot advance without losing ships. An example would be:
a) Melee naval can't get next to a city, as skirmisher units will rip it up.
b) Naval Ranged begins city or coastline bombardment.
c) City will use either a ship garrison or a produced ship to snipe one of my ships, as it doesn't have melee protection (generally happens once anti-warmonger gets high enough).
So my fleet either just sits outside of range and hangs out, or I commit to the engagement knowing I'm going to lose ships. Which is very dangerous, if your fleet starts to shrink, you can get absolutely crushed by a rebuilt AI fleet, or another AI that declares on you.
I think sometimes I just get very impatient with naval combat. I go into open water, see a monster fleet from the AI...have to run all the way back to my cities so I can soften up the fleet and then take it out. It just always feels that no matter how many ships I have, its never enough...I will lose some of them as I engage the enemy, and inevitably that new vulnerable costs me as the AI recovers.
I think I'm rambling a bit on this point, there's just something about naval combat right now that's irking me.
I think there are 3 problems with naval combat as of right now:
- An attack force consisting of just Naval Units is basically useless against continental coastal Cities. I think you need to combine your Naval Units with Land Units to get anywhere because reliably killing Land Units with Naval Units is impossible. You also can't use Naval Units to pillage enemy Roads. Even if the attacker manages to take a City with Naval Units they will almost always not be able to hold it against Land Units.
- Numerical advantages/disadvantages play a much bigger role in naval combat than they do with land combat. Naval Units are much faster than Land Units and they never have to face rough terrain. As a consequence Naval Units can gang up on each other much easier than Land Units and the party with more Units will have a much easier time making use of all of their Units to attack the enemy. The AI of course has a very large numerical advantage on high difficulty levels.
- Naval combat is much more deadly than land combat (both because of the higher mobility mentioned above and due to healing restrictions). In order to not lose ships you'd have to either be playing super safe or you'd have to be winning extremely hard. An AI player can afford to lose a large part of their ships, a human player can't.
For me the above three factors usually make me neglect offensive naval combat until I've managed to snowball through land combat.