Sounds like a good basic program. I'm assuming you'll be teaching him low-bar squats? I would suggest that you progress slowly form-wise as he is older and perhaps should deadlift from an elevated position at first until he can work his way to deadlifting from the floor eventually (i.e. rack pulls or something along those lines), for squats something similiar.
Work the flexibility/mobility work into the workout and warmup would be my suggestion. (i.e. in between squat sets work on some hip/ankle mobility drill, in between bench sets work on thoracic stuff....etc)
"And for crying out loud. Don't go into the pain cave. I can't stress this enough. Your Totem Animal won't be in there to help you. You'll be on your own. The Pain Cave is for cowards.
Pain is your companion, don't go hide from it."