What was the first official pro game where the 3-3 was played after AI started suggesting it?
I great question that would very much deserve its own thread. 
If we find out the result should go on https://senseis.xmp.net/.
Probably not a specific answer but I thought it was interesting and maybe a clue
This changed when Li Zhe 6p famously proclaimed that the 3-3 invasion’s function was actually to rob the hoshi of its base, and that a simple kakari instead would be too easy on the hoshi.
Li Zhe demonstrated this impressively by invading at move 7 vs. Li Xuanhao 6p
There was a post/ thread with YT games from Nihon Ki-in with English subtitles. Please help me find it because search is useless. Iirc they were older, like start of the century?
I don’t mean the YT videos that are out there without subtitles, there was specifically a post/thread with subtitled YT videos.
You mean the NHK Cup ones?
This channel has uploaded several of them, and some of them seem to have good subtitles as well.
I remember there being different videos as well, and searching for them at some point. I assumed they might’ve been removed by YouTube, though.
This?
Edit: never mind, that’s not what you asked for.
Yes, the name seems familiar, that’s probably it.
I had some videos bookmarked but they now appear to not exist (I guess they were deleted), so couldn’t find the channel.
It seems that unfortunately there are many deleted videos, but I’ll search the existing ones.
Assume that you are playing on an infinitely big board (infinitely long on both sides of the X and the Y axis). A ladder starts with no ladder breaker in sight. Can the stones being laddered survive?
Depends on board + position. An infinite board can still have edges.
I think I get what you mean… Changed the description a bit
How does scoring work?
One possibility: fields have different point values, like in pyramid go, but such that the total amount of obtainable points is finite.
In such a setting it’s possible that the game is decided after a finite number of moves, i.e. when the amount of “contestable points” is less than the difference between “secured points” of black and white.
But ladders make that whole theory go “poof” 
Same, the one with more territory wins. But that’s irrelevant here though that’s also interesting to think about.
How does the game end? If it doesn’t, the laddered stones can be saved and thus are alive. Because they can not be captured, they just run forever.
Is there a keyboard shortcut for these thingies?
Especially hide and poll.
What about adding a “local Positional Superko” rule? You may not play so as to recreate a 19x19 position about the most recently placed stone?
Hmm that may work but that would mean that any ladders spanning more than 19x19 would not be possible anymore 
That’s the point. Otherwise games can take infinitely long to finish. which was the problem you posed
Not really. How long the game takes to finish is not significant here. The question is whether a stone that is constantly being laddered but not able to be taken from the board considered alive or dead.