Yes, but the input and withdrawal of fiat money can be controlled.

I wonder how in this case the user protection will be implemented functionally ? After all, external payment systems can not be tied to smart contracts?

There is already a scheme that allows you to exchange this way: the one who wants to withdraw the cryptocurrency to the fiat money must lock it in the platform , then the second participant transfers the fiat, and both confirm the deal. I'm not sure exchanges will happen this way on this platform , we need to check it out .

It is unlikely that fiat will be introduced to the platform, the website has the exchange scheme described above, ie the money will be transferred through external payment systems.

This is a misconception that crypto-currency transactions need to be anonymous. Many holders do not try to remain anonymous, they are ready to be recognized . And such a platform will only simplify the use of crypto currency.

Yes, many governments tried to regulate the crypto currency, but they have failed . They can forbid it, not regulate.

This is the regulation of exchange markets, not the crypto currency. The streamity platform will be decentralized, and it will be impossible to regulate it.

This depends on the way how the money will be transferred, of course, bank transfers can be tracked. But there are other more anonymous ways.