I am by no means an expert, and like you most of my photography is a hobby, with a few late exceptions (last year, where I have had about ten paying photojobs on the side of my regular work (mainly to pay for more gear:) )
A couple of things strike me about the shot. The composition of the shot. It is a bit prisonlike
, and you have a lot of space over his head, while cutting his limbs by the elbow.. If I recall you shot him at 125 with a 70-200. I am not sure how much further back you can move, but you can certainly move the zoom back so you get more body, and less dead space above him. Also as you have noted yourself, move him away from the backdrop, and then you have to choose whether you want a low-key or a high-key photo. If the latter then you need more light on the background, as well as a bit blurry. The light in your son's face is a bit flat (the shadows give depth). The white balance seems off, but that might be my screens.. A tad green, but more so on my iPad retina, and less so on my laptop, but I guess that you are shooting in Raw, so that will be no problem to fix afterwards.
Another question is what do you want this photo to be? A character study of your son, or getting focus on his medals and stuff? He as far as I can see have beautiful eyes, and maybe you should work with that?. Get him in a pose that is not straight on, but a bit turned to the side? If the focus is the boyscout, maybe a portrait in their natural environment?...
Just a few thoughts. Hope this helps.