I think of an 1800 (USCF) rating as the point where a player stops making obvious blunders--"past the blunder stage," as one person here put it. I estimate I was somewhere around that stage at one time, though being busy and changing my repertoire in recent years have hurt my playing level for the time being. A 1600 rating implies you're still making blunders of some sort.
I also don't really understand the common emphasis on controlling squares, unless there is a clear potential threat of say a knight attack or hole where a knight or other piece could be outposted. I can't see that my playing has ever suffered because of that neglect, especially when an introductory book says something like my d4 move is controlling the e5-square: Big deal--half the time my opponent has a locked pawn there that is already protected, so such a comment strikes me as almost useless.
One thing that has been helping me recently is playing Computer Level 10 on this site. If you think you're "past the blunder stage," that program will quickly change your mind! I'm relearning in a different context what I already knew: virtually every move in chess is critical, and even the slightest inaccuracy will likely be punished, and will definitely be punished if you make more than one inaccuracy, at least against a very strong player.
Another thing that has helped me is studying database games, although that can be very time-consuming. By studying how various less popular moves were exploited it eventually becomes clear why the best moves are in fact the best, and how to exploit the weaker moves. Databases also contain implied statistics on the best piece placement, though it is very painstaking to extract that information by hand, since a complete summary requires perusing at least hundreds of games by hand. Poor piece placement is a surprisingly common source of errors, even for masters. Databases also show the continuation of book moves so that the plans behind the moves become clear. Plans are very important, and it sounds like you aren't understanding those if you're only looking for tactical plans. Since opening books are usually so poor at describing plans, you'll just have to do it yourself.
For example, what does White have in mind with an unprovoked h3? We usually assume it is to prevent a bishop pin via ...Bg4, but another important reason for that move is to clear the h2 square to put a knight there. (For example, in the following recently posted game, a 2200 player here fell into that problem by not understanding the plan behind ...a6 in the King's Indian Defense: https://www.chess.com/forum/view/game-analysis/nice-game-which-i-lost) A less common reason for h3 is to prepare for a kingside attack via g4. Another reason for h3 is to provide Luft against back rank mate as the endgame approaches. Such reasons for moves become clear by going through entire games in databases, but again, it can be very time-consuming. But then, does any player really expect to get good without investing much more time to study?
I started playing chess about a year and a half ago, at the age of 46. I knew the basics of how pieces moved, but nothing else (I'd move my rooks out first in a game). In the last year and a half I've played a ton of games on here, studied some on my own, watched videos. Lately, I started doing tournaments that were dedicated to particular openings to try to get a feel for them. For some reason, I have been crushing with the Danish Gambit against much higher rated players. My rating when I was spending time studying my openings and on my moves for daily was approaching high 1500s, but then I got busy with other stuff and found I had too many games at once, had to make rush moves without much study, and have dropped back to low 1400s.
I used to play 10 minute games a lot when I started, but stopped a while back because I felt I would do better taking time at this stage of my learning. Since I got caught with too many games and too little time, I have stopped initiating new games and I'm now down to a manageable level.
I had a thought that now that I have some more time, instead of starting new games, I would go through every one of my old games, organize them by opening, and analyze them to figure where I made mistakes. WIth hundreds of games, it'll take a long time, but obviously I'll learn a lot, maybe seeing where I make the same mistakes, and probably learning more opening theory/lines along the way since i am sure I made a lot of flaws in my openings. It seems like if I just keep playing games, without going back and doing detailed analysis, I'll probably make the same mistakes over and over and any progress will be very slow.
It seems like I have plateaued and am not really improving from just playing games. Maybe self-analysis will lead to a break through, but I'm not sure. I think I do not know how to look far head, or make positional plans rather than tactical plans, or evaluate my opponent's positional or long-term plans. I don't really know what the value is of, say, controlling a certain square or a certain color, I just look for tactics and, if I see none, I try to make a move that makes sense to push for some kind of advantage (setting up attack, pushing a pawn, defending against tactical threats, etc.), and I may play a good positional move, but not based on any long-term positional plan.
At some point, I'd be open to coaching, not sure when that would make sense. I have a list of chess books to read, but have not had time to dive into that. I thought of going to the local chess club to play in person on a weekly basis, not sure if that would actually improve my game, but it might be fun.
Well, not sure what kind of response I'm looking for, but if anyone happens to bother reading this and wants to throw out any observations/advice, I'll be glad to read it.
Ken