As I am an animal health tech, my advise may not be worth much. You know what free advise is worth! You sound as if you are doing things all right. I would say grate him if he is chewing on things when you are gone but otherwise if not and potty training is good let him run. As for chew toys don't give him plastic, not good for insides. I would get dent-a-bone or rawhide bones for him. Having his food out all day is good as that way he does not over eat and, could, get sick. Also get him some of those toys that he can get his teeth into so that you can play tug-of-war. Picking up water a 9pm is good so no accidents is good also.