I would be very wary of sending my dog anywhere where they "sort out their problems" for you...
It sounds to me that Dusty is anxious... to be honest I wouldn't be encouraging her to approach people - she obviously finds it stressful and, while she does it to get a treat, it could be heightening her overall anxiety...
Our dog can be wary of people, but she generally just avoids them.... we've had huge progress recently with people coming to the house, as she's been able to switch off and ignore them (which I have rewarded)... if I were to try and encourage her to interact it would make things worse.
One exercise that you could do would be to take Dusty on-lead somewhere with not too many people and plenty of space. Take a clicker and lots of treats... walk along and, as soon as Dusty sees a person, click and treat and, at the same time, take a step away from the person - that way you are rewarding a calm reaction to seeing someone and teaching her that she doesn't have to approach people she is uncertain of.
Have you considered T-Touch?? It might help her...
Also, if she is particularly anxious when people reach down to her, it would be worth getting her eyesight checked.