Sounds good - thats kind of like me as well. I was just wondering so I could figure out what you could work on, and give actionable steps to improve.
Chessable is a great way to improve btw, I got two courses for my birthday, and they've been amazing. You said you like to get a small advantage and grind the endgame - in this case, I would recommend you get Magnus Carlsen's Endgame course. It's taught by the world champion, and imo it's really good.
For now, just study the Aagard book - he has several other books too, on Attack and Defense, and on Positional Play; all of which I think would be beneficial. He's a very good author and most of his books are available for free online.
If you just want to improve your overall understanding of chess, it's important to just watch a lot of chess. You get exposed to a lot of playstyles, openings, etc. That's how I improved quickly.
The Youtube Channels you are watching are excellent. Just keep that up Just make sure to avoid "opening trap" videos - they're fun to watch, but are detrimental in the long run (I fell into the trap of watching them when i was ~600 and I tried them in every game. Things didn't end well)
As for openings, I play a ton as well. It helps to have a diverse repertoire. Just watch some games, experiment on your own, and see what you like. Experimentation is an important part of chess, so I would recommend you get an account on a different site, where you don't care about the rating as much, and just practice openings, or new ideas you learned. Failing fast is, surprisingly, a very good way to improve.
Discovering I have some work to do to get used to reading chess books, lol. Checking a board, etc. while reading. I'll figure it out. Anyways, tomorrow I plan on starting a rating run on lichess while trying out a couple of different openings. Chess.com being my main rating play for the openings I am actually familiar with, anything I get used to I can start playing here. I expect to fail and mess up a good deal, so I suppose the real goal is to keep playing and losing even as my brain screams at me. Eventually I'll learn the patterns and main ideas until they become habit and instinct, just have to take that step.
Anyways, something I wanted to ask, do you know the best way to store custom puzzles? I'm looking for a place to stash a bunch of them. I want to be able to start a puzzle without knowing if it's checkmate or not, etc.
its a video by Gm. Igor Smirnov of most common mistakes