For the paint question--it depends on how thick the little flecks of black are. I'd try to polish them out before putting on light ghost gray. It might be as simple as rubbing them hard with a dry cotton ball; or try a little toothpaste on a cotton ball or Q-tip. Then wash in detergent and water. If that doesn't work, you might have to use 600 or finer grit sandpaper. As for filler, straight super glue (either gap-filling or regular thin) can be used without talcum powder.