a) It's Tri-X. Frankly, while it's good, it's not *that* good. Sure it's iconic ("cult following" says it all) but frankly I think that's more in the name and history than the emulsion, particularly because Tri-X is not now what it was 10 or 20 years ago. Can you honestly tell me there is something you can do with Tri-X that you absolutely cannot do with some other film like HP5? I would find that really, really hard to believe. I think the loss of TMY2, Portra and Ektar will be a bigger blow to photographers than an old-style B&W emulsion that isn't very different from at least one (profitable) competitor's product.
b) While I'm sure I can't make Tri-X in my shed (and I make a lot of shit in my shed) and I'm quite prepared to believe that Tri-X is more complicated than an old Efke emulsion, I don't think that's relevant. The fact that Ilford can competently and profitably manufacture HP5 and all the rest on a smaller scale is a good demonstration that similar films can be made on a smaller scale. No one needs to be able to make 10 rolls at a time as long as some small company is happy to make 1000 or 10,000 rolls at a go.
c) Stockpiling, whatever. Certainly if you depend on a particular film for your particular style, if you buy enough to last you a while then you know you'll be able to use it for a while. You're kidding yourself though if you think the manufacturers will even notice your sale in one direction or another, even if you buy a thousand rolls - that's peanuts in the scale that they operate on even in these reduced times. That's only two cartons of films, and the big distributors buy the stuff by the pallet. You are not going to prop up Kodak by buying a huge personal stash now instead of later, and you are not going to sink Kodak by using up a stash instead of buying a couple rolls each week. Don't forget to factor in a couple hundred $ each year for freezer electricity costs!