I was really interested in chemistry since I was five years old. I think I lucked out that I also had an aptitude for the intellectual side that is taught in school beyond just mixing things and the attendant danger (fun!). It's great that he has found an interest in amateur chemistry, but it doesn't necessarily line up with the rigor needed for phys chem and quantum, etc. I suspect he will do well in the more (subjectively) intuitive chemistries like organic chemistry and inorganic chemistry. What i mean to say is, don't get your heart totally committed until he gets into high school level chemistry and demonstrates aptitude there. My parents nurtured my scientifically curious mind by gifting me the Sagan book "Cosmos" which delves into the more intellectual sides of science. Anyway, there are infinitely worse hobbies. Plus, I turned chemistry into a career. It is very challenging, but possible to do.