By not killing Benny when I found him at the Fort, I lost the Virgin Mary Pistol.
It is always a good idea that whenever you fast travel to a new location to first look around to make sure your companions are with you. Otherwise, you my end up retracing your steps (or reloading) to get them back.
While playing, always use a timer set to go off every hour. Save your game when it goes off. That way, should you need to restart the game, you will only lose an hour of game-play.
Next playthrough, try for a Survival skills level of 30.