1) Sure, but this wouldn't give him any protection. On the contrary, there would be a ton of extra liability and exposure if he were to refuse to process a levy.
Shares don't need to be held in a brokerage. There's always a process to identify and seize the property in question.
2) There's no such thing. TSLA is a US public company, traded on US exchanges. It's simply not possible for shares of the company to exist outside of US jurisdiction.
Just having a share certificate doesn’t make it s bearer form. The corporation would have to set up this ahead of time. I don’t know the status of Tesla shares that he owns but it would be very weird if they aren’t registered securities. It would also raise a ton of questions if they started issuing bearer shares after a court injunction.
(1) Would it be legal for him to own the brokerage?
(2) What if he moves all of his stock in offshore accounts?