Out of curiosity, how bad is to keep driving when it is obvious the EGR was stuck open like it was for me? If its have troubling running due to being leaned out by the EGR vacuum leak is it also causing some serious detonation in the chamber? I wouldn't want to melt a piston over so small of an issue as a clogged EGR.

EGR causes the combustion chamber temperature to be reduce. Without EGR, combustion temperatures go high enough to form N2O (nitros oxide). The EGR keeps the temps below this temperature.

But the exhaust gasses also contain some unburned oils and hydrocarbons that will coat the back of your throttle body plate and intake valve stems.