GSD puppy agressive, fearful

Question
Male GSD 6months old. Got him at 10 weeks old, probably bad breeder, although the parents & brother seemed great. Now I know he was not socialized at all. I took him to puppy classes right away, tried to socialize in dead winter, walked him, took him out to stores. He has always had fears, when walking, from sounds, at night, very cautious and wary. Now he barks at everything he hears, growls when people come in, at other dogs. I have taken him to doggy daycare since he was 13 weeks, now he starts fights (female boxers). he gets neutered Friday. He is better on a leash walking and with his people shyness, but appears aggressive with dogs on a leash, still not sure if i can trust him with 1 & 3 yr old grandkids. He nips. We have tried to do Alpha Dog training, went to class twice a week with a very good trainer. Will the neutering help, how can we curb the barking...he is so alert he will not look at us or seemingly hear us. We love him and want him to behave. he is fine with us in the house...except barking at every sound. he is beautiful, will be about 100 lbs.
Thank you

Answer
Neutering will help, but may not be enough.  You are already doing much of what I would suggest.  Perhaps just more of the same.  Take a look at http://www.dogbreedinfo.com./topdogrules.htm  They have some additional material on dogs and children you may find useful.