a large safety pen is most likely a 16 gauge
•The first Safety pin was first used in the 14th and 13th centuries B.C.
no if it is made entirely of steel.but a part of it can be an insulator i.e. the end cap if it is made from an insulator material.
they can barely rust and that is in water
you could but it would really really hurt and it most definitely would get infected as you can not sterilize a drawing pin without a lab full of chemicals.