With key mags and start, master off is a useful safety item. Past both on, and the starter could kick.
I'd rather handstart with no-one in the cockpit than with an untrained person.
After several starts of a Jodel O200 with it stopping before I could get in, a senior big plane engineer offered to help. As I approached the cockpit to get in after starting, I thanked him, and said to close the throttle while I got in. He pushed the lever fully in, the plane jumped the chocks, and zig-zagged about on the apron, with brakes seizing wheel on ice patch, then allowing movement on dry bits. He froze for a while before closing the throttle.
NEVER let an untrained person swing the prop.
PS in cold conditions I've started Pa28 engines with the primer out, closing it slowly after start