Flyboy, if you can spare the wood, you should be okay to work around the splinter. So far as tillering with the power sander, I would steer clear. It takes a little more time to do it with a file, rasp, gizmo, and scraper, but you can't take of too much wood at one time. In my last bow, I used a pair of scissors to do the final scraping, and it worked wonderfully. It makes sanding a breeze, and gives you precise control of removal. FWIW.
Good luck on your bow, and let us know how it comes out.