MSTR's coins (and Saylor's personal stash as well) are not exactly "locked up", but I otherwise agree with the overall sentiment of your post Dabs and your various other points including that MSTR nor Saylor are likely to be either selling or attempting to be manipulating the BTC price, even if they are capable of doing whatever the fuck they want - in terms of free market aspects of bitcoin (but of course, there would likely be concerns from some regulatory bodies (such as SEC - and even share holder concerns) if Saylor were to try any kind of significant or meaningful levels of selling stocks to buy lower kinds of things).
His personal stash, maybe he can do whatever he wants with those, but I am guessing he has those under multi-sig and it will just be a hassle for him to actually do it.
The company stash, it's also very likely to be multi-sig with the board members, and the whole company has to agree. Maybe he has more signatures, but I'm almost sure he needs at least one more other person if it's set up correctly. There may possibly be a last resort backup plan like buried in some high security vault.
Maybe? We are just speculating. Imagine that one dude who has hardware wallets all over the planet and he's just a family man.
Most of these guys have their own "castles" ... I mean houses, or office buildings, with adequate physical security. If you had an actual gold bar, you could safely store your bitcoin paper wallet in the same place. Multi-sig would just require more than one of these safe places.
Also quite possible that Saylor has all the keys anyway, so he can still control all the bitcoin of the company all by himself, I'm still pretty sure it's in some form of multi-sig either case.
How do you think he stores his bitcoin? 18k BTC personal stash, and company coins 108k BTC ... ... You have that much, better put they keys in some building with armed guards. Be your own bank. Literally.
The board is definitely not a multisig, it wouldn't make sense for several reasons. First, with any company, the board generally doesn't have access to bank accounts for the company so there would be no reason to give them such access with bitcoin through a mutlisig setup. It's cumbersome and needlessly bureaucratic, and therefore unnecessary. Also, the board doesn't really have any power to check Saylor due to his super majority voting power, so there's no reason for him to share responsibility with the board. They serve as figureheads only with no real power in the company. You definitely wouldn't give people like that responsibility to control any part of the company's day-to-day operations, which again would be needlessly bureaucratic.