Sanding won't hurt a thing, as long as you don't remove too much wood. Go slow. Remember its easy to take wood off, hard to put wood back on.
Tried a jigsaw on my first bow, and quit using it after about 5 seconds. Like trying to cut a brick. Bought a low tpi blade I want to try on the next one, but what we really need is a band saw. Oh well, hand tools work fine, I just gotta sweat a little with them.
Search the bowyers bench with your questions and you'll learn all you could want, almost any question I've had has already been asked on this forum, and these guys are the best bunch around, you're gonna be hooked.