In an early, conservative implementation, all of that could be offline except the shareholder votes, which would be automated on chain. The board would be beholden to the chain decisions via normal lawsuits in offline courts.
In a more radical setup, the board votes could also be done in software. More radical still would force arbitration onto the chain.
What will be interesting to watch in the coming decades is to see how much of the workings of a company can be done in software on-chain.
It seems uncontroversial to say you could do shareholder votes there though… and that’s the minimum required for the scheme like this.
You will definitely be able to short this stuff on a crypto exchange.
Just like a USD short account you’d have to stake some capital, probably in BTC or ETH or something like that. And you’d have to hold enough crypto to pay your recurring short fees. And in the even of a margin call you might need to put up more capital.