Would like advice from professional dog trainer on 9 week old puppy!?

Ok first off the pup was taken from mom and litter mates to early. That is the first thing working against you. You are going to have biting because normally if the pup stayed with the litter and he bit his litter mates to hard the pups would either bite back or yelp and stop playing. If he bit mom to hard she would put her mouth around his neck and pin him to the ground to tell him she has had enough. So you tapping the dog in the nose is not communicating that you mean enough. You are actually doing the opposite and enticing him to play. Dont tap or hitthe dog he is a puppy not human so it does not have the same meaning to him as it does to us. You should only give him a sharp no. As far as walking a.9 week old puppy he is way to young to umderstand heel. Right now he should just be getting used to walking on a leash period. The come command should only be used for fun right now and never scold him only praise him no matter what if he comes. If he did do something wrong use an entirely different word like get over here or something like that. The sit command at his age should be just that. It does not matter if he gets up the point is he sat and he gets rewarded. Dogs only know black and white. Always use hand signals for each command. Pups of that age should only be learning one command at a time and training sessions should be no longer than 15 minutes. Once he has sit down pat you can move to the next command. The next command should be stay to follow with others.