If they have some good examples of their work, I don t see why not. They should obviously have a clue as to what they re doing, and their prices need to be reasonable, but as far as age, a good photographer is a good photographer. Also, a family portrait probably doesn t necessitate Ansel Adams, so it s completely reasonable that a 14yr old can take a good picture.
Probably not. What I may do is enter into an agreement that I pay only if satisfied with the end product. Or, since he is aspiring, I may agree to give 4 or 5 references for him in lieu of payment.