Good questions, and I disagree with Rothbard on the answers.

Re police.

Private police will be for rich people, transport corridors and commercial precincts. Like the old days.

Working-class neighborhoods will have an old man sweeping leaves and asking "Oi! 'Oo are you?" if you don't look like you belong. And someone else with a rifle behind a blind on an upstairs window watching to see if you pull a weapon.

Like many "ethnic" areas of my city today. There are surprisingly few f_ckups, when one happens its all over the news for days.

Re corporations.

Without the State, who will defend the Board's interests against their managers?

And who will defend the managers' interests against their workers?

Without Big Daddy Government, tens of thousands of pages of legislation and regulations, and a myriad of tax-fed agencies, Big Business will die so fast you'll think it was a conspiracy.

Yeah, we can still have self-executing DAOs living in some blockchain, but if there's no corporate personhood and State enforcement of their rights, then what happens at the linkage between the DAO and real world assets? Private litigation / arbitration is what, and the DAO structure will be at a competitive disadvantage vis a vis sole traders and partnerships.