#2 Draw when you perceive a threat. I draw, and release the safety upon completion. Use the drawn gun and verbal commands, "Stop or I'll shoot!", to force the perp to back down or to effect your escape. If the threat escalates, do not hesitate to pull the trigger. Don't wait until the last moment to draw, you may not have a last moment at that point.
A perp approaches with a gun in his hand, pointing at the ground. You draw yours and point it at his chest. He stops. "Drop the gun!" over and over. As long as he's not advancing and hasn't raised the gun, there's no need to fire. He's in your sights, if he even twitches that gun hand or continues to advance, you have him cold.
The simple appearance of a potential victim who's suddenly armed may be enough deterrent. Like I've said, crooks like it easy.
Drawing is a first resort, firing is a last resort.