I had to stop watching. The master volume should be left alone imo. All volume changes should be done in the mixer channels I believe the master volume should be used simply for fading in or out. Thats just my opinion at least.
When setup up a static mix you must set the master output. Once you have you use control room output to set or change monitor level. While mixing you need to watch master output level and may have to adjust it a little here or there. Not sure why you would think you never touch the master.
