Hi
Too much growling? The only problem with growling is when there is no response from the dog and you keep doing it. He seems to be responding every time you growl so i think it is just his short memory span
Your right about the play methods as he is too young to have outside yet. Dogs will often get exercise and enjoyment out of a simple sit, stay and come game. Chew toys and things like that are fine as long as he only chews that. I don't have a huge problem with chase games as long as it is not you that he is chasing. Look at what he enjoys doing and try to think of a game that will let him do that but won't get him in trouble
Good Luck
Todd Field