>>946733-Food - A jar of PB works as well as anything for emergency food for less then a couple weeks, and it's good bait for traps.
-Water - You need some sort of container and either a dropper bottle with iodine or bleach or a water filter.
-Shelter - If you can't build one from nothing, you'll at least need a bivvy/liner to stay warm and dry in inclement weather.
-Warmth - Your ferro rod technically covers this, but a lighter is better. You wouldn't pack a needle and thread instead of a suture kit, would you?