The step-son is 25 not 10.
My brother is getting close to 50. He comes over and torments Cujo, pushing, pushing pushing the dog, staring into his eyes, pushing him, teasing him, riding him (not literally). My mom asks him if he wants to be the first one the dog has to bite. Mom will not put Cujo down if he takes a chunk out of her son. Should she???
This thread seriously saddens me too. We have a puppy here that was abandoned and emaciated before being picked up and dropped at a shelter prior to eight months old. The shelter says he's happy and friendly -- do we know how long they had this dog? And the OP gets the dog, and for seven months has been working with the puppy with the advice of a couple of trainers.
I commend the OP for being loyal to the puppy. I think that maybe the type of training and leadership is not necessarily right for this puppy. And maybe, this pup has genetically weak nerves and no training will be right for it, we do not know. But without someone with good experience who can evaluate the dog, how can we condone any type of action, except management so no one else gets scratched.
I am sorry, but a bite is NOT a bite. When a GSD bites, yes there will be bruising and punctures, and possible stitches. otherwise it is inhibited. A dog that inhibits their bite is STILL giving warnings. Just not the kind of warnings we want them to. But still the dog is not hopeless.
I think people have failed this dog much more than this dog has failed humans.
I hope that we give a pup with a really rocky start a chance, and not just kill the dog because it does not act like someone's puppy that has had all the benefits of good breeding, a good whelping situation, training and socialization experiences, and consistency in the humans that owned it. Of course this pup is going to act differently, might need more training, and the owners may have a tougher road to travel.
Lastly, I suggest that the owner build either in the garage, basement or fenced back yard, a kennel that the dog cannot escape because it has concrete base, nine gage wire and covered over. When there is a question, put the dog in his safe place and keep people away from him. Management is not so painful when you know the dog has a safe and comfortable place to be when the man is there to work on the furnace or the grandkids are over. Having such an arrangement does not mean you lock the dog away forever, it just means you can put him somewhere safe temporarily.