Without spending much time, the defined terms are the most obvious change that I'd make if I were starting over. Although we all know what "loose impediment" means because we've been playing for a long time, "debris" would be a more straightforward word for it. Likewise, "through the green" could be "the course, other than greens, tees, and hazards." These are just the ones that come to mind right away.
People that have been playing by the rules for long enough to use these terms know what they mean, but the time to learn it would be shorter if the terminology weren't so archaic.
Those books you refer to may dumb it down, but they become a lot more wordy in the process, and the better ones include illustrations. They also only prepare the player for some of the most routine applications of the rules, and anyone who has played for any length of time knows that playing golf goes far beyond routine. It's a complex game, in part because of the size and variability of the playing field and of the equipment used on that field. As a result, the rules must reach a level of complexity that can address all of those variables in an equitable manner.
From my first time golfing, I could 2 putt from just about anywhere on an easy green (the kinds I play). Even if I couldn't *really* . .I was close enough to believe I could. If you can do that, the best thing is to work on long game, imo. I could practice putting a long time and still not make many long putts . .so I'm still going to be 2 putting unless I hit it closer. If you struggle to 2 putt once you're on the green, could be a different prescription. If you *feel* like you should work on your short game more, you probably should.