To sand down the chipped spots go to one of the big auto parts chain stores and in the paint dept they sometimes carry a small pen shaped device that has little glass strands that protrude like a ball point pen. 3M makes one oddly enough named "Spot Sanding Pen". You just rotate it around on the paint chips and rust spots and it leaves a nice little round clean bare spot roughly about 3mm in diameter. Dab enough paint to fill in the spot and lightly sand smooth when dry.