Dog Biting Inhibitation?

Since i was little i have been fond of German shepherds,but wanted a certain specimen a big stocky straight back one. I eventually found a breeder in Leeds and he gave me a Czech working line German shepherd. I never heard of a working line dog, but ever since i got one i have been really interested in the dog protection criteria. My cousin knew this guy who has two German shepherds and works them, so he gave me his number and ever since we have been good friends. He introduced the pinch collar to me and said if he is going to do protection with my dog i need to get his obedience good, so when you say sit he has to do it without holding back, when he looks at you on a heel you don't bribe him using a ball he looks at you because you tell him to. So i listened to him and he showed me how to train with a pinch collar which is called pressure training which my dog could handle. Today he got a bite sleeve on, and my dog was biting him just as a game, he said we need to build up his drives now, then he will apply pressure and pain so the dog is stiumlated by drives but doesent see it as a game. What my querie is does that sound about right what you need to do getting a protection dog?, obviously i know not every dog can be a protection dog, it needs to have it in the genes, and even then they have it in their head but you need to bring it out.