All the above problems you name are down to bad sociolising as pups and could have easily been averted. Here's a simple analogy. Take collies, now you go into any remote farm and chances are the collie on that farm is going to bite you ... why ? Because it has had very limited contact with humans and so sees anybody as a threat ... yet the same breed attends crufts in their thousands to compete in agility dance and obedience and all are perfectly happy walking amongst hundreds of thousands of strangers. Why ? Early sociolising.