Borrowing isn't binary. There can be something like 2000 shares available to borrow. He takes it all, makes a profit, subscribers get nothing - that's well documented online.
OMG!! So he's screwing his own students? LOL They paid to learn to make money and they ended up making nothing then I guess. Glad I never jumped on his bandwagon.
Work for what? Entertainment, bragging, some extra cash? What you should be asking yourself is - if I dedicate years to get good at this, will it make enough of a difference in my life? IMHO, if it can't be reasonably scaled, it's not worth pursuing. At some point, when you are very good, you want to be able to press your trade to catch that fat tail that makes a difference.
Not a scam, he is selling information. All information can be found for free but the point is it's packaged nicely to short cut your learning. if you wanna learn fast don't be afraid to invest in learning.