Your points make sense to me as I am following a similar path.
I have been playing chess on and off for a very long time but never made a serious effort to improve. Wanting to change that, I started:
1. Playing more chess (here on chess.com as OTB opportunities are sparse for me).
I play mainly online chess but try to move at an OTB rate (my goal is to improve my OTB, I have no interest in correspondence chess). After the game I look through the post-game analysis offered by chess.com as feedback.
2. Studying tactics
I am over 2000 on chesstempo, but here with the clock constraints I hover in the 1600's. I find it hard to improve (my peak 1799 was at the beginning, it went downhill from there) but then again I am less than 2 months into this new routine.
3. Studying endgames
There is a wealth of possibilities out there. I chose to study the blue diagrams from Dvoretsky's Endgame Manual to get a grounding. Worked through some 50 position related to pawn endgames and now working on rook endgames. Unlike many players I like studying endgames, so this is a breeze.
4. Reading Master games
Unlike you, I did not start with modern games but am reading through Morphy's games currently. I feel like I am learning a lot from this, but retaining the information is a challenge for me...
5. Opening Repertoire
I do not have an opening repertoire although I have played some openings quite often. I started a huge number of tournament games on chess.com - often thematic ones - and play various openings to see which ones are too my taste. I may do this for a year before deciding upon a repertoire. I don't know how well that will go because I find learning openings the best method to fall asleep instantly.
I see you do this in 10 minute games, which is good too of course. But for me online games are better as I can fit those in more easily in a busy schedule.
6. Studying Strategy
I have not started this - apart from reading Nimzowitch several decades ago. I have the books on the middle game by Euwe and Kramer and also the 3 volume set by Pachman. Of course the previous topics contains already so much work that it may be a while before I get to this.
I don't know how this plan will work out, but the journey will be interesting. Best wishes in your endeavours!
But your openings both with white and black are excellent.
I currently have a standard rating of 1345. Certainly not good but better than I had a year ago. I tried different methods in the past to improve but things only got worse. I am now trying a novel approach which may or may not work in the long run. I believe it has allowed me to win 17 of the last 20 games plus a draw or two. This is what I'm doing:
1. Staying focused as much as possible (age 73).
2. Watch GM games to get a better understanding of how they think like Magnus, and Gary. It seems the moves of major and minor pieces by GM's are in preparation for the End game more than anything else. Understanding this took time because some of the moves lets say a minor piece in the middle game made absolutely no sense to me. The other consideration was control of space and I am useing this in my games.
3.The last thing I do is play 10 minute chess not to win but to experiment positions and just have fun.
Your thoughts and comments.....
Andy