I played some more and I have a few more questions
1. My vassal germany seems to be constantly voting for proposals I vote nay for. Bismarck spammed great diplomats and has more delegates than I do now while I've just put spies in there. He comes to me with deals that say I will vote exactly what you do not want and in return give me my cities back. Is that even normal.
Sometimes civs make weird offers that make no sense. In my current late game, I've been working on my relationship with the Iroquois, and they've started pitching deals where I pay them to vote against a proposal I just made two turns prior. It's like, no, you don't get it, I
want Casus Belli. I'm the one proposing it! No, I'm not giving you Lapis to vote against it. Go home, Hiawatha, you're drunk. Damn fire water.
2. Is Eiffel tower a bad wonder. I built it because I needed a negative boredom modifier in all my cities and it gave me a meagre -5%, meanwhile pocatello builds the brandenburg which would given me a free great general that would have synergised nicely with my UA (japan).
I never chase Eiffel as Japan. If I can grab it easy with a few turns, sure. But otherwise, much better things to do by that point.
3. Austria keeps asking me to accept their embassy for 1gpt and I've always refused. Is there any point in an embassy? I can not get open borders or send diplomats there and manipulate world congress. It also means no DoF but is there an advantage to not accepting embassies?
Early on, it's about revealing your capital and letting rivals know too much about what you're doing and capable of. Late game, it's still about cutting off access to information, but it's also about pissing them off. Current game, I've spent centuries intentionally refusing an embassy to the Mayans because I didn't like the company they kept (they were too chummy with Spain for my tastes). The Mayans finally DOWed me when they should have known much, much better: I'm 15 techs ahead of them, 200000+ faith with 800 faith per turn, and Zealotry. They're about to join the Japanese Empire, it's going to be swift and disgusting, and they did it to themselves.
4. Should I go for Iron fist as I have 2 vassals now or lebensraum because I have 4 great generals and would likely build citadels in a war with russia. I might still go for science victory or diplomatic because I'm also considering getting the cs bullying tenets later. Also is 60 a good cap for 190 population and 9 cities or should I start spamming some citadels and armories?
I like Iron Fist on general principle, but by then my vassals aren't going anywhere anyway. I've burned their cities, crushed their populations, brainwashed their children, sold them jeans and have them all paying too much to watch my movies by then. IF is a nice little insurance policy, though, if rebellion/liberation is a potential risk.
Running Japan, unit cap is lifeblood. It can't ever be high enough, due to war weariness. When you're late in a crucial meatgrinder war, you don't want WW to ruin things for you. So if you have the safe opportunity to bump the cap up, do it whenever possible.
While I was warring with venice every AI kept spamming the ban luxury proposals, world religion and scholars in residence. God I underestimated scholars in residence, people who were in industrial instantly went modern. They have now banned tea, cocoa, ivory, spices, jade, silk and I have one of everything.
Diplomacy and espionage. Train as diplomats, send to CSes, divide civs against each other whenever you can. What I enjoy doing is having diplomats in the lead civ capitals, and shopping that civ every time they sneak attack someone. Sow mistrust and dissension. Intrigue everywhere. Play on fears. Then use those advantages in the Congress.
One Congress tip that took me
years to realize: when a civ votes for one proposal, that's a vote they can't put to another one. Just because the tooltip says that such-and-such proposal has 25 yeas, that doesn't mean it does, because those votes may get put on another proposal. So play priority proposals off against each other. I've actually scored World Religion before that way when everyone was busy arguing over some sanction or other.
I played this game for years and only recently have I really started to take note of the diplomacy game. It's an incredibly, incredibly big deal. Manipulate, backstab, hold grudges, give payback, lie, cheat, steal. It's true what they say, you really
can steal more money with a briefcase than with a gun. So pay close attention to those relationships and developing vote blocs.
6. How do people use great scientists in vox populi? I am making 850 science a turn and the great scientist's instant yield is only 2800 and this after the rationalism tenet that boosts popping yields by 25%. In general I think great person improvements are better in vp.
I still follow the old vanilla rule: academy until public schools, then bulb every one after that. Works for me.