While there are a few things to work on, he clearly has good instincts. A lot of kids make the mistake of waiting for the ball to come to them or stretching to make contact. Your son already creates space for himself and makes small adjustments. I also see an engaged attitude and as TCF mentioned already, he is on the balls of his feet and displays good energy.
Looks like you have yourself a player!
(4) Yonex VCORE Tour 97 310. PPPP 18 @54/PP SG @57. Ultimate Player's Tweener.