What sort of "blower" are you refering to.?? Roots type.Centrafugal,Axial (my favorite but bloody hard to get)Wankel type.Blowers(Roots) don't stop working at big RPM's,they just become inefficent,that is the air is heated (thined out)to the stage that it's energy co-efficent drops (there is a formula for it some thing like 7 PSI boost at 25 degrees K (kelvin scale)has the same oxy content as 30 PSI at 40 degrees K )Big reason for intercoolers.
Yep they are all Mechanically driven (belt or gear)Some S/C have internal pressure relief,some external relief and "NO' a standard fan-belt (single V) would slip (check out the belts on any of the 4agze or 1ggze)