Dryrider, you show a certain amount of naivety when it comes to defending your home. Just being in the Army doesn't prepare you for home defense.
A handgun loaded, with a lock, or in a safe, is very little protection at all. At 3:00AM, you will not be roused from a sound sleep and be prepared to defend yourself or your wife. If someone has entered your home, and they can be almost noiseless, and no matter how you think, they can be on top of you before you know it. Any intruder who is closer than 21 feet will be on top of you before you can open a lock or a bedside safe.
Unattended guns do not go off by themselves. You, or your wife, have an inordinate fear of a loaded gun. You may as well have an unloaded gun, as to have one with a trigger lock, or put in a bedside safe.
Your marksmanship badge only means that you can hit a target at 75 meters-plus with an M16, or a Beretta M9 at about 10 meters. Hardly the measure of hitting a target in dim light, when you're scared, your heartbeat is running at 180bpm, and the adrenaline is flowing like water through your veins.
Firing warning rounds, as others have mentioned is not to be done. If you've had basic infantry training, you have undoubtedly learned not to give away your location needlessly. Warning rounds do that. And a warning shot will probably go through your water heater.
Perfect practice makes perfect. You can't leave the gun by the bedside and expect to protect yourself. The real world doesn't work that way.