Hopefully, Denver will answer your questions;I'm only a student too
My opinion about S&T is this: The main benefit is the reduction of lateral body movement, and this allows for a more repeatable golf swing.
We all seem to have a tendency to over-swing with the driver, and this,IMO,leads to even more lateral movement during the driver swing than with the iron swing. My swing key with the driver is to keep my lead knee from moving aft (away from the target;) I feel it is moving perpendicular to the target line during the backswing. The knee reverses course during the downswing, when the leg wants to straighten, and the knee moves straight back.This helps keep me steady by reducing the lateral movement;however,it doesn't "feel" very powerful. I do think the technology of the driver is straighter than any other driver I've hit or owned. So, combining the driver and a centered swing has proven to be very effective at hitting fairways.
I don't know anything about compressing the ball between the club and the ground. It is not something I even think about with a driver or iron shot.