I had the same problem with the blue banks. I was told by the other MSC that I was disqualified per the bank. Then I tried to do one at RSG and was told I was disqualified by the bank. So I heard the same store from both MSCs.
Both MSC's told me they aren't told the reason why.
The first MSC said that once you are gone, you are gone forever.
RSG told me that they see shoppers get reactivated all the time.
So that was a difference but otherwise I was hearing the same thing from both MSCs.
Re the wings shops. I rarely qualified with the previous MSC. I've done all but one in our area. I had no problem signing up. The other one is on our board, but I haven't tried. However, I thought with the new MSC there is a 180 day rotation per location. I could be wrong about that, but that is what I thought I saw.