Ok, I have a question about the thinning quills. Do you notice it when she isn't balled up or stretched in some way? If you could share a picture of a thinned spot that might be of some help as well.
Next question, the quills she is losing, are they fairly normal? By normal I mean fairly straight and have a bulb at the base and skinnier at the base and tip.
When you took her to the vet last month did they just give her baytril or did she get any additional medication? What did they say about the ear gunk?