Ash, Why not give them a chance with him? I'm starting to question this an awful lot. Someone with a wealth of experience and complete knowledge of his issues has offered to take him and work with him and you still say no. You'd rather put him down????You ask how would we feel if our dog bit them or their family member? Well, I'd feel bad if they didn't know the risks, but they do. I'd feel much worse putting Chester or Millie to sleep if I could possibly avoid it. They would, I'm sure have him supervised at all times until they either got a handle on him, or could predict any bad behavior before it happened. I will be VERY disappointed if you follow though on this decision without giving them, and him a chance. I know Chewy isn't the dog you hoped he'd be, but he still deserves a chance. He may be a totally differnet dog with them. Dogs can adapt and change their personality with different people.
An extremely confident and strong hand may be what he needs. You may also find out that he doesn't need to be the alpha, or maybe he would be the alpha in their pack.