depends on how many pops you want to give him for his inside skills.
in general though, yes 6'2 is painfully slow for inside skills. What skills do you need to pump him on? If its inside shot, then you could consider training 1n1 for Forwards, instead of 1n1 for guards, because this will suppliment his IS (1n1 for forwards trains Dr, Hd, and IS :))
If he needs ID, then yer, it's a bit of a tough road. What is his ID now?
Rebounding is a bit easier, because RB training is two position training, so you can always have him be part of a wider Rebounding training program and its easier for him to get 48+ minutes during the week.
but really, its going to depend on his starting inside skills, would you like to post them here?