For 32 reasons, I installed cameras around my house this summer and fall.  I have lots of memory in my computer, and two monitors.  One monitor is dedicated to viewing the outside of the house.  My system is not that expensive, and it is nice to see who is at the door before answering it.

Wouldn't cost much to install a camera to view the front door to see who is there before unlocking it, if you are a lady by yourself.  It is a wise investment.

As for the unloaded gun, I was taught not to show someone a gun as a threat until you are prepared mentally and physically to shoot another human being.  INMHO, an unloaded gun is not protection, and would only anger someone intent on doing you harm.