Just an aside regarding speed limits - these were introduced in Europe not for safety reasons, but in response to the oil crisis of the 70's which prompted governments to enforce limits to cut back on petrol consumption - not deaths. Perhaps it was the same in the States.
Slow driving often leads to drivers becoming distracted or sleepy - ergo accidents.
Fast driving (as opposed to plain negligent driving), usually envolves a driver who is alert, and so long as he is not reckless with those around him can normally respond faster to traffic and emergency situations. IMHO.
As a rule I like to drive powerful cars not for their top speed, but rather for their ability to allow me to manouver, overtake quickly and safely.