Default OCing profiles are helpful when you don't know how to go about.

Not necessarily the most efficient, for example an overclocker will fine tune to get the best out of the voltage vs speed to maximize efficiency.

Some profiles would push the processor beyond limit too, so in the end what's seen there may not work.

BSOD - hard to comment, usually settings incorrect.
Electrick shock - check your home wiring, especially how the electricity is grounded. use good quality socket / plugs.

If you "Restore to default" and it's settled then yes, settings problem.