Update on Blitz: In my opinion things have taken a turn for the better for a few reasons. My family and I are now aware of his aggression and how to control him, prong collar and video arrived. The training video was not a huge help as Blitz is trained in the basics (just needs more quality training time), the prong collar is however a different story.
We pretty much strapped it on right away making sure that it was correctly adjusted and in the proper position. On leash
with the collar on he is a different dog. Absolutely no pulling, the slightest touch of the collar brings him in line in terms of walking, he is however wise to the collar.
For example if the prong isn't on he understands that he can pull again. I've have also noticed that he is getting used to the collar and more pressure needs to be applied now than previously to get the same results.
I have only corrected him hard a couple of times and that was for trying to attack another tradesman (the same ones as before, he recognizes them and quite frankly he hates them and senses their fear). Upon correction he gave a bit of a whine and obeyed my sit/stay command and basically just stared them down instead. I've also gotten him used to his crate and the tradesmen now know not to enter without permission.
I don't think his protectiveness will ever dissapear (which is perhaps a good thing). For example if he sees someone walking around outside he will circle the inside of the house to whatever window they are closest and go nuts. On the positive side he has shown nothing but playfulness around children, this is where I make sure the correction around children is consistent, to make him understand that little kids are boss. My little cousins take him on walks daily, play with him and their friends daily, no problems.
He is very playful around children but I do supervise just in case the kids start fighting and he gets protective etc.
He's also settled down somewhat since getting used to the new house. Couple other things worry me about him, I weighed him last weekend and he's only 77 lbs that seems underweight for a nearly 2 year old GSD (he gets fed twice a day). Other thing is a front leg limp that developed last week after an intense session of ball chasing (going to vet tomorrow).
Derek: as for giving him away, no way! He's my son <img src="/ubbthreads/images/graemlins/smile.gif" alt="" /> I could never get rid of one of my kids.
Theresa: I'm not working him on long leads, but I should be.
He doesn't really bolt but then again if there are distractions in an outdoor environment he isn't 100%. e.g. other dogs will distract him. If we're not at home, strangers don't really interest him unless they do something weird.