Ok your math checks out, however this goes into the question of what Chapter 11 bankruptcy does to the NOL's. Correct me if I'm wrong, but the 30% is correct, however only under normal circumstance. I only read a rough synopsis of bankruptcy law but from what I gathered restrictions can be greatly expanded when considering NOL's being transferred from one company to another through buyout. This is where I've wanted others to check my research because I'm not an expert in bankruptcy laws. If your 30% is in fact all they can pull, I agree with your statements and things get exponentially more complicated for current SHLDQ investors. However I believe it's much higher than this. It also played into the theory of why Eddie signed SHLDQ into bankruptcy in the first place. It would have been less hassle for him to just buy out assets through a purchase agreement rather than going through bankruptcy court if he just wanted to take assets and run. From what I've seen, Eddie filed for bankruptcy due to the lifted restrictions in buying power from a hedge (his holdco) and the lifted restrictions gained towards tax breaks (NOL's). All that said, great job on the research, let me know what you find.
Edit: Forgot my damn links again. Below is a couple chart breakdowns of SHLDQ assets/liabilities. I'll also add a few links to simplified NOL's and how they work links. Nothing too big there for someone like yourself but it had a point or two in there for me I was unaware of.