Yes, breaking contact would stop electrocution. This is why electricians (at least qualified ones) touch suspected open wires with the back of their hand as the strong electrical current will force their fist to clench the wires harder this causing internal...frying.

The main effect from electrocution (a misnomer, since getting electrocuted means the electricity also caused your death) pretty much depends on the voltage. At low voltages all you'll feel is a tingle but go high enough and you're dead.

Electoruction kills in one main way - the electrical current is strong enough to cause the heart to either stop beating or flutter - killing the person potentially without leaving any physical marks. If the voltage goes higher your body conducts the electricity to a certain degree, the more voltage the more the electrons want to move (layman's terms here), if you'll have a shitton of electronics moving fast and rapidly and in huge numbers throughout your body you're basically gonna get burned/cooked - either the organs or your nerves.