> Remove access to healthcare

US doesn't have single payer. You pay for it out of pocket (if it comes from your employer, well you're exchanging service for service instead of service for money).

> Remove access to courts

This would be unconstitutional. In the US you are entitled to a fair trial even if you aren't a citizen.

I like this, as well. Remove access to the justice system. If you aren't participating in society, there is no reason for society to lift a finger to protect you from theft, assault, fraud, deportation, etc. Subject them to the same entry restrictions as anyone else crossing a border into a country.

Sovereign citizens will very quickly discover that participating in society provides them with a lot of value.

Half the American population uses private health insurance, but yes. It is better to lose services than to go to jail or have your home confiscated for not paying taxes. And some people can choose to join mutual aid societies that provide these services on a voluntary bases.

If you want to opt out of taxes, the legal remedy you are seeking is renunciation.

https://en.wikipedia.org/wiki/Statelessness#United_States

Do they lose access to police protection as well? Would it be possible for someone else to forcibly take that house?

Naturally: policing is after all a state sponsored service.