I've shot several rifles in this caliber. The 17 Fireball would certainly fit the bill for any of the purposes you have listed. There is no recoil. Accuracy seems pretty good. You'll certainly notice that wind can have an adverse affect on the accuracy. I'd say that, in the proper hands, you'd be able to whack a woodchuck out to 300 yards or so. One concern is that the round is pretty limited in its usefulness...paper, woodchucks and crows are about it. Another thing to consider is ammunition cost/availability. For your nephew's purposes, a 223 or 22-250 will do the same thing and ammo will be a lot easier to find. Plus, you have to deal with the fact that the 17 Fireball, being a new cartridge, has not really been proven. What happens if ammo sales plunge in a couple of years and they quit loading the round? If it was me, I'd buy a rifle with a more common chambering. Just my .02!
Jason