Disclaimer: This my first GSD. I have trained Labs for years but a GSD is a different animal. I AM NO EXPERT!! That said the only reason I am responding with my limited experience is I had/have to some extent the same problem. Only difference is Auron would bark at every one or dog in public. At not quite 4 months he would hit the end of the leash with every hair on end charging at dogs that were 3 times his size that were just minding there own business. With people the aggression was not as pronounced but still there. He had been well socialized as a pup by his breeder and even taken to Schutzhund club with her older dogs. I take him to the city square 3 or 4 times a week as well as feed stores and every place one could imagine as well as to my own Schutzund club. He is actually very social and loves people showing no aggression once they approach and are deemed ok. At that point he would go to jumping on them like a complete monster. Never having a GSD training in Schutzhund before and not having anyone close to consult (my club is a 275 mile round trip) I was terrified to use any physical correction on this 3 or 4 month old puppy from what I had read and seen on video. I tried it all. Auron jumps up. No Auron and walk away. Auron bites me, no Auron, redirect to a chew, Auron barks and charges dog or person, No Auron and walk him the other direction, ect, ect, ect. Sure it stopped that particular instance but next time it was the same thing. I finally had the chance for the club to see him for an extended period along with a well known trainer from Europe that we had a 3 day seminar with. Long story short I was told I had a future monster on my hands UNLESS I got control of him now. I all ready knew this as I know a hard dominant dog when I work with one but was afraid I would mess him up. I was creating a brat that with his genetic back ground would be a train wreck waiting to happen. Our puppy trainer even went so far to say "That dogs going to bite you one day if you don't do something" Having trained dogs for 20 years I knew what to do and just needed the "permission". That night in the motel we went to work. I went to pet him and he bit me. I had done the squeal like a puppy thing, no Auron thing a 100 times. This time I grabbed the little "Germangater" by the scuff and shook him till HE squealed telling him no then walked away. The look was priceless! One more "treatment" a few days later and the biting me is cured. Same with the jumping up. Instead of using a complete stranger and possibly starting some association I had a friend he knows and likes come around the building corner with Auron on lead. We walk up to him and of course he jumps up. One time I pull him down and give him his no command. Of course he payed no attention. When he jumped again we had another scuff "treatment". A couple times and he is pretty much cured. Does he still get excited to see me and mouth me for a second or make a half jump when someone reaches to pet him? Sure he's not quite 5 months and just a puppy. I expect that and am not going to tare him up for it but if it starts to escalates he will get a sound that he knows means "better knock it off". With strangers uptown or dogs he is ALWAYS on a leash and in his case a fur saver on the live ring. There is a difference in a person just walking down the sidewalk in the middle of the day and someone in the shadows behind a dumpster or a aggressive acting dog and one that is in his own yard minding his own business. The dog knows the difference. When he goes to barking at the person/dog minding its own business I simply tell him to knock it off and continue on my way. If he wants to make an issue of it I will give him a appropriate pop on the lead and walk away from what he is barking at while getting him to focus on me such as asking for a "watch" or maybe doing a quick setz or platz. The distraction is good to practice his commands with as well. I don't make a big issue out of it. We also go set on a bench on Main Street square right before the 12 o'clock workers get off for dinner and just set and watch them walk around us while we get pet and just talk.
This appropriate discipline started almost a month ago and I must say both of us are much much happier. There is no resentment as before he receives ANY physical correction we BOTH know it is a willful act on his part for something he understands. I do this on a Schutzuhund breed dog that has been looked at by many people including the well know breeder and is know to be a strong dog. All the biting, jumping and barking has nothing to do with fear on his part. To my knowledge he has fear of absolutely nothing which I really have to watch or it can/has got him in trouble. If a dog were barking out of fear at strangers I would never do any of this. I'm not saying to use slam yours to the ground by the scuff on say the jumping up. Yours may only need to be slightly kneed a couple time to stop it. I'm may catch a lot of grief for this post as some people do not believe in any physical correction but with certain dogs they need some IMO. I would never use physical correction if positive training will correct the problem but some dogs will insist on being the boss unless told other wise so to speak. If you have any doubts as to your dog is fearful and confused or just being a brat and dominant have several knowledgeable trainers look at her. I truly have not tryed to offend anyone just offering a possible solution that has worked on a certain kind of dog and I only hope I have made sure what kind of dog I am talking about. Good luck!