Well, the thing is. I precisely did the hull that dark because the wraith ships you see in the show are all of em even darker.. i mean, the problem is, i will need to replace the whole texture because if, as you say, try to put more brightness into the black spots, the texture starts losing a lot of quality. The original texture was far lighter, but as i said i tried to keep the dark tone of the ships from the show. Besides, fiting the texture to the whole model was already a lot of work :) , and it was the texture that looked more "organic" from the ones i had. I will do some tests.
PD.: Also, what do you mean with "dark grey spots"? there is no grey anywhere.. :) about the uniformity of the texture, yeah, thats one problem i noticed in the beginning but in the end i adjusted it somehow and trust me it looked far worst in the beginning xD. The dark spots on the texture were not there originally, i made em. I could do something similar using another brush or something like that with a lighter tone.