In my second rerun I decided to do things a little better, especially concerning starting moves, played till after liberalism, to which I was the first, but I had little land (did manage to colonize the closest island, but that's just two cities, and rather backward ones for still some time to come)
After the wars started out, I got discouraged and decided to rerun. I had, unfortunately, been hasty in deciding my diplo moves towards the countries in the other half of the world, and I ended up being friendly with Mansa, whom I wanted to attack, and unfriendly with Bismark, who attacked Mansa and Alexander, I think.
~~~
Third rerun
Started out with BH as a tech and a warrior as a build. When it was acceptable to do so, I started out on a worker who was ready at about the same time as BW, so he chopped a forest for the other warrior and the next worker, I think. When AH (second tech) was ready, I started teching agriculture and working on the cow pasture. When the second worker was out, I started training a settler into which I placed two chops. Then, one worker started building a farm and as soon as the wheel was ready, the other started roading towards my second city, the copper city.
After this point, the order of the moves is somewhat foggy to me, I do know that due to bad land, my second city started out on a worker. Anyway, built the mine, roads, and started training axemen. In the meantime, I settled two more cities, one south of capital, for production, and one south of copper city, for commerce.
As for techs, after the wheel was done, I took writing, to boost research up a bit, then pottery, then maths.
While teching maths, I decided to attack Kublai Khan, remembering from the previous rerun that little land = unhappiness for the player, at least if that happens to be me.

I sacrificed A LOT of axemen, but I was eventually able to conquer three of the cities Kublai had, plus autorazed another. Without catapults, taking the capital was very difficult, but when the opponent is limited to one city and you have units blocking their access to tiles and keeping their workers behind the walls, victory is only a matter of turns. I was eventually able to defeat Kublai Khan.

I also managed to experience both sides of the battle luck coin: I lost an axeman who had 95%+ chance to win, and I won a few battles with 30%ish percent win chance.

(Although overall, I think I was more lucky than unlucky)
After maths was done, I made the first HUGE mistake of this rerun: I looked upon my paralyzed cities due to jungle tiles, so I teched IW. Bad bad move... it took me 30+ turns to get IW (marathon), and then 50+ to get currency. I also had the chance to observe something I had never encountered in my games before this... mainly because I don't normally have so many cities so fast: not having enough projects available for building in cities due to lower tech rate. I was actually training fishing boats which I was offering as gifts to Qin, and in the two non-coastal cities I was training swordsmen which were getting dismissed as soon as they had been trained, in order to keep maintenance low. Even so, I still had to keep research at 10% or 20%, I had to keep a lot of scientist specialists in my cities just to be able to have any kind of tech rate towards currency.
As soon as currency was ready, I started building wealth in almost all of my cities and this allowed me to take the science slider to 70%, which offered a GREAT boost.
Well, that was that, played along after, took optics at some point and got the circumnavigation bonus, teched some techs, met other civs. At this point in history, I was researching education, and here is where I decided on a dramatic approach which in the end proved futile.
After this point, I decided to train a lot of catapults and macemen to attack Qin and take Beijing from him. He had a lot of wonders there, so taking the city would offer a great boost to me and would be a huge blow to Qin's progress for the rest of the game. I finished education, then teched liberalism, took astro as free tech, built galleons, filled them with about 10ish catapults and 10ish macemen and declared war on him. Landed my units near Beijing, and precisely next turn, Qin came and slaughtered almost all of my army with his xbowmen. I still wanted to try, though, so I at least tried to bombard the city defense. 10 catapults only managed to take the city's defenses from 150% to about 130%, so at that point I decided to give up.
I haven't yet decided whether to give up altogether, or whether to continue from the time in the screenshots, when I was still developing.
I also feel like I'm backwards, technologically speaking, it's the first time any civ had astro before me, and that doesn't feel too good.

I guess that going up in difficulty also means that one must give up on a lot of advantages one took for granted in lower difficulties, so I might need to get used to barely having any kind of a tech lead, or even being behind in science, but for the moment, it feels discouraging.