Only gangstas carry autos with an empty chamber. That way the surveillance tape at the convenience store shows them racking the slide so they can look "serious."
The well made, well maintained 1911 should be safe to carry with the hammer DOWN on a loaded chamber due to the inertial firing pin Browning included in the design. I've tried to set off many primed cases by hammering the hammer, and I have yet to get one to fire, but when the hammer was cocked and released, the primer would go bang. The half cock notch is there as a fail safe, last ditch protection against dropping the hammer while cocking, but it doesn't always work.
Cocked and locked, along with learning the manual of arms--that's the way to go. The grip safety is a redundancy which Browning did not want, but the US Army did, and they were paying the bills. He didn't think the gun needed it. The grip safety on one of my 1911s doesn't work, but I really don't notice it. I do think about it, however, and whether the grip safety is a redundancy or not, I'm going to fix it just so the gun is "right." I honestly can't think of too many ways it would save you from an unwanted discharge, unless perhaps something got stuck in the trigger guard while drawing the weapon; as the grip safety locks the trigger, you might be saved from that possibility.