Draw length is a matter into itself. For a quick check measure his wingspan and divide by 2.5. That should get real close to what he should be shooting. As for the feathers touching his chin? Mine do and I fletch my arrows 1 1/4" ahead of the nock groove. So if it bothers him, and his draw is right, what's to stop him from fletching a bit farther down the shaft? Say another 1/4" or so. By experimenting you find out what works for you.