We also had a dog that was afraid of people when she arrived. She came from a similar circumstance--she was kept in a barn the first year of her life.
In our experience with building Macie's confidence, it seems like she learned the most from watching the other dogs. Even after 8 years here we can see that she still is not the most attuned with humans...but she picks up a lot from the other dogs.
We are lucky enough to have a fenced in yard and not many visitors. That made it a little easier to get her used to strangers. Our good friend started coming over now and then and always would get down on his knees to say hello to the dogs. At first Macie hung back, but she saw the other dogs were having fun and started coming up to him, too. Eventually, she stopped shying away from him completely. Gradually, she got to the point where she's now very people-friendly.
Does she have a good people-friendly doggy buddy that she could learn from similarly? Maybe in a fenced yard or a dog park? Some place you can use during a quiet time of day and enlist friends that your dog doesn't know to come in and just interact with her buddy in a calm way? Never force her, just allow her to see that her buddy has no fear... I think eventually it might do wonders. Especially if that human friend of yours has a delectable little snack on their person.
As for the loud noises, we have another dog, Grace, also a rescue, who bolts at loud noises. What we started doing was to make noise while she's anticipating dinner. We feed them in metal bowls. Starting from just an inch off the ground, we started dropping her bowl in front of her while she was focused on the fact that dinner was about to be served. Slowly we banged the bowls louder. The desensitization seems to be working, at least for sharp percussive noises like bowls banging. Not so much for lower, long-drawn out noises like thunder or the figher jets on maneuvers.
What does seem to help for those other kinds of sounds is to make happy noises ("Oh, yay! Thunder! Hurrah!") and bring out her favorite toy when it's storming or the jets are overhead. Sometimes all it takes to build a little confidence is to give them something happy to associate the noise with...