If your pedals are coming loose, somethings wrong. I don't even tighten mine to specified torques. Loose pedals have never been an issue on any of my bikes.
As for what I carry in my saddle bag.... a couple hex keys, small screwdriver with changeable points, a tube and a CO2 inflator. Oh... a house key and maybe some stuff I've long forgotten. Other than using the house key, everything else has been unused and just extra weight.