We all come to a forum like this to try to learn or share something about the piano. So I'm going to try to contribute as if I was driving along next to it on a slip road.
My contributions is this: If you want to read a really focused, thorough, and up-to-date tutorial on piano technique, then here's where it is (it's a link to the book which which this thread began).
https://practisingthepiano.com/new-ebook-technique/The author is very generous in that there's a lot of information he's placed out on the internet for free. So there's a lot of worthwhile stuff for pianists that that website can lead you to ...
I'm pointing this out because this particular e-book is one of the best resources now available on piano technique. PLUS, it's more innovative than most e-books because its not just simply text and pictures. There are video demonstrations included as well. And on top of this the book is well-written. Meaning, it's well organized and it's very easy to read.
If you're in need of a thoughtful resource about piano technique, a resource that's up-to-date with current research and pedagogy, a resource that's well-written and easy to follow, then
https://practisingthepiano.com/new-ebook-technique/ is where you want to look. In the interests of pianism in general I'm just pointing that out ...
Other books I could recommend (but the link above would be my first choice in any event)
https://www.pianopractice.org/https://www.amazon.com/On-Piano-Playing-Motion-Expression/dp/0028722809/ref=sr_1_fkmr0_1?ie=UTF8&qid=1385819954&sr=8-1-fkmr0&keywords=gygory+sandor+piano (this one's a bit expensive but ...)
As long as I'm leaving links about .... some blog posts I've written about the pianos and selecting them and playing them.
https://www.polishookstudio.com/search/label/pianoBut, first and foremost, I encourage anyone who wants about the best most concise resource there is to be had these days to take a look at the e-book that's the topic of this thread. You'll learn a lot from it, it'll save you time in the process, and it should be pointed out as the fine book that it is - for students AND teachers AND other professionals.