Those nobs are good ones to have, the toggle switch if working should keep the arc going once you hit the gun trigger, push the trigger again and it will stop the arc, nice to have when doing alot of welding, (caution) when you leave your welder to get a cup, shut it off so if your cat jumps on your mig gun and the trigger gets hit, could come back with the whole roll of wire on the ground or melted on your tractor bucket.
Spot Time> sound like for tack welding. Run In>> adjustable wire speed for arc start, then goes to what you have the wire speed on, good one to have. Burn back>>>adjust the wire length that automatically burns back when you stop welding so the wire doesn't get stuck in the puddle and helps on restart, good one to have.