Jack, Toothpicks most likely will not hide the hole and may in fact, look more obtrusive than the hole that you are trying to fill. Most wood, once saturated with epoxy, takes on a darker coloring than when dry, and different grain within the same strip can take on different appearances as well. In my opinion, it will be extremely difficult to match the color of the surrounding wood by using the end grain of a toothpick. Most people opt not to try to hide the staple holes; however, if you are interested in trying, my suggestion would be to use colored latex caulking - the type that comes in small toothpaste sized squeeze tubes. I've had the best luck with a brand called, interestingly enough, "Staples". There are various colors, any of which can be blended to achieve custom colors.

Steaming the staple holes will help to close them up slightly, but will not appreciably hide them once the epoxy hits it. As far as the steam damaging the glue between the strips - it won't - it may soften it ever so lightly initially, but once the steam has dissipated, the glue will dry as good as new.

Joe Greenley