So I actually really enjoyed this post- the free-wheeling style of it and attempts to explain something that's caused a lot of hand-wringing. (Namely- Manafort's inexplicable legal defense strategy right now)
But there's a big gap in the argument. It's actually pretty unlikely that Mueller's team will need to disclose any classified information about their investigation in order to succeed against the jurisdiction-based motion to dismiss. Between publicly available information, existing case law (US v Libby- as the author points out), and the broad mandate that established the special prosecutor- there's likely more than enough information to deal with the motion.
But even if Mueller's team does end up having to present details on their legal strategy re: Manafort, there's absolutely no obligation to share that with Manafort and his attorneys. Being a plaintiff in a case against the Executive doesn't grant you defacto high level security clearance. What would likely end up happening is Mueller's team would give the judge a high level description of how Manafort fits in, and the Judge would rule with that information in mind but without having to share any of it with Manafort's team. FOIA lawyers usually try to avoid having the government disclose any classified information in their cases for this reason- it puts them at a big disadvantage.
Ultimately the Judiciary isn't going to force the Executive to compromise an ongoing investigation. When it comes to sharing classified information, they tend to side with the Executive.
So I think we're back down to three possible explanations for Manafort's obtinance:
1) He's fighting back to show Trump that he doesn't want to sell him out and is hoping Trump will extend the pardon that was dangled in front of him by Dowd
2) He's terrified of the Russian government. Steel (and what are assumed to be some of his sources) are reportedly on a GRU hit list right now for their role in things. Imagine what they'd do to Manafort if they thought he was going to talk
3) He's as much of an egotistical sociopath as we all assume he is based on the kind of work he does and is actually convinced of his own invincibility.