Yes a relay would would work and no it does not go dead in the "start" position on a GM. They use a second wire up from the starter solenoid to give the coil full battery voltage in the start position.
You sure? I used to have a column lock column in my old Landcruiser from about a 70 GM and it certainly did. That old girl had various, a 360, a 340, and 318 before I gave it all up
I already explained the solenoid "I" wire. It does exactly the same job as IGN2 in a Mopar
