[floridasl22002]

This is the bit that concerns me the most.....

"4. With the engine running ( normal conditions ), I notice that when the brakes are pressed the back wall of the vacuum booster presses outward toward the front of the car. It also moves the master cylinder with it and flexes the brake lines a tiny little bit. I don't know if this is normal or not."

Brakes are the difference between you and a hospital bed, so IMHO never take chances with brakes. If you are unsure, get an expert to look at it.

It could be worth while just calling in to somewhere like "Just Brakes" and have them check it. They will obviously want to do the job on your car if they find anything, but that's your choice. Better to be safe than sorry.