Trust me, if you do an honest 20 rep program, at some point Jesus will talk to you. On the last day of the program, he asked if he could work in.

The spine is best at bearing a load in an arch

Strength is an excellent example of a physical characteristic that drives improvement in other athletic parameters. More strength means more power, more endurance, better coordination, and better everything else. This is why, all other things being equal, the stronger athlete is the better athlete.

I like musicianship, and it's quite lacking in most modern popular music. You're always safe with old Chicago, the Allman Brothers, Gov't Mule, or Tower of Power.

Most of the problems with the bodies and minds of the folks occupying the current culture involve an unwillingness to do anything hard, or anything that they'd rather not do. I applaud your resolve, and I welcome you to the community of people who have decided that EASY will no longer suffice.

On resting in between reps: It varies with the length of the set. 5s or fewer get a breath to reset. Longer sets might take 2 breaths. During the last few reps of a true 20RM squat, just do what Jesus tells you. Trust me, if you do an honest 20 rep program, at some point Jesus will talk to you. On the last day of the program, he asked if he could work in.

I recommend against a wooden squat rack, for much the same reason that I recommend against a wooden car.