Aw, she is a good dog!
Honestly...your dog sounds awesome and reminds me of my childhood dog, Duke, who we suspected was a husky/GSD mix. We got him as a puppy from the pound in Phoenix, but he was an outside dog for the first half of his life--we played with him and took him for walks, but otherwise he was out in the backyard. He was never properly socialized with people or dogs, and became quite aggressive to strangers as he got older. (I was 4 years old when we got him, so I take no responsibility for this!)
He actually ended up biting the neighbor girl while out on a walk when I was about 6-7 years old. It was a pretty bad bite on her forearm. My folks took him back to the pound, but he only lasted about an hour because we all were really sad so we went back and readopted him. We then got him neutered soonafter, which actually seemed to solve some of his aggression problems--he became pretty chill (and admittedly a little overweight). He was never exactly social, but he never showed any aggression to anyone ever again. We never once had him work with a trainer, and I'm pretty we didn't do much right when it came to training him ourselves.
Still...in hindsight, in my mind's eye, he was the perfect dog; he lived to be 16! He was so smart, but he had HORRIBLE recall until he was too old to move very fast, and definitely had that husky independence streak. Of course, I only remember the good things about him (and rarely think about the barking, the digging, the never coming back when we called him, the stubbornness, the prey drive with cats, how he always wanted to dominate every other dog he met), and can't help but compare everything Willow does to that childhood dog, which isn't fair to her.
So anyway, your comments in particular, and my memories of Duke, make me hopeful that Willow will come round with her fear aggression issues. And even if it takes a while---Duke had his problems, we didn't know what the heck we were doing, but he had a good life and we loved him until he died. So just because Willow might have issues doesn't mean we can't make it work. :-)