1. It sounds like you're effectively making your own stock exchange, but with crypto instead of cash. I imagine the SEC will have many things to say about that. It could be legal, but you're not going to like the laws they'll make you follow.

2. In a real stock exchange, the company value is largely the volatile thing. In one backed with crypto, the price of a company will fluctuate more from the asset you're buying it with than the company's activity itself. If the price of bitcoin goes up, I own the same number of shares but worth fewer bitcoins. That seems like not what folks into crypto care about.

3. If a company puts all of its shares into this, it likely cannot ever ipo. That's going to turn off most investors. I would expect it's an all-in endeavor.

4. Companies accidentally losing their private key for unissued shares sounds like a very bad failure mode.