Wow... what a long post.
But I got sucked into reading it with your title; I'm also guilty in writing long sentences and using a lot of comma's 😅
Not as you though.

Anyway, I think I had to un-learn it at the beginning of my university years. The teachers instilled in us, the importance of being clear in your reports and/or essays. Something may be clear in our heads, but not to the reader. The readers can't read our minds. We also needed to break every variable down and define almost everything.
Anyway, when writing posts here on Hive I catch myself shortening sentences and learning to use those punctuation marks more frequently. It also helps to accentuate something you want to say, to say it in one sentence. Still learning to curb it though.

I don't think I ever read anything of Hemingway, but those sentences you've mentioned made me want to try some of his work out.

Wow, what a long reaction.
Enjoy the new week! 😊