> I remember I saw some website which allowed you to select some 960 position and it would show like some commentary on how to proceed as either side and what should be prioritized and showcase past games with the same position, this was like a year or two ago.
Computer generated? If so, I wouldn't be worried. Besides, imagine this scenario: you search for a 960 game on Lichess right now, you or your opponent have 25 seconds to move. In 25 seconds, you can't input a 960 position into another site and learn theory for that very specific position. If you take longer than 25 seconds to make a move, Lichess aborts the game automatically. It's not possible. 960 is a completely feasible variant if you want to avoid opening theory. Also, a big 960 tournament will be played next year^, so things are getting exciting in the 960 world.
>By middlegame theory, I meant that there is a lot of resources on Chessable that go into middlegame theory of an opening if both sides played early opening by the book, so even middlegame is quite covered in terms of variants and the otherwise general strategy ideas are actually incorporated as part of the theory and studied as such.
I have two things to say to this: 1. you should know the plans and ideas for the middlegames you get because these middlegames arise from your opening repertoire, which you should have already studied (pawn structures, best piece placement, common sacrifices, pawn breaks, etc). 2. as you say the theory is influenced by strategy (and tactics), so if you have a solid strategical foundation (and tactical), you will be fine as long as you're not playing an extremely sharp opening, in which you must know concrete theory. A book I found extremely helpful for strategy was: Mastering Chess Strategy by GM Hellsten.
>As for endgames, I don't think the theory is too difficult but it's also been a situation where people are guided towards books like Dvoretsky's endgame manual and 100 endgames you must know and stuff like that which again is just thrown at you and told to go study it because a lot of the people read these books.
Those books are not for beginners, especially Dvoretsky's Endgame Manual. I agree with you. If I were to recommend an endgame book to a beginner, I would recommend Silman's Endgame Course by IM Silman. You're a strong player, though, so I think you could get a lot out of Dvoretsky's Endgame Manual (at least the grey/blue sections, which Dvoretsky's notes as being the most essential parts).
>Now, generally, I agree, you can play Chess by intuition to a really good level but I've had games where my opponents just told me my moves were sound, made sense and in a way they were "good" but they fell to a part of their preparation theory that was like 8-9 moves deep
What was your opening repertoire?
^ = https://en.chessbase.com/post/freestyle-super-tournament-in-...*