It sounds to me like you're doing all you can do too! Chores and daily activities will be good for him. It will get him in the habit early of cleaning his living space so that once he's out on his own, it will be second nature for him. For me, it's been an adventure and a half, and has taken me 5 years away from home and my girlfriend to whip me into something closely resembling shape. Since you're not home a lot, I would recommend getting him a puppy or kitty if possible. Having an animal around will provide companionship for him if you're not around, and it helps to teach responsibility.

As far as him understanding himself, I'd talk to him and see if there are any activities he'd like to become involved in, and be supportive of them. Growing up is the time to figure out what you like to do, because once you're on your own... there's quite a bit less time for that. For getting your family to understand him, well... I'd say just plan family nights and activities for the weekends (which you seem to be doing already), and try to see him in as natural of a situation as possible.