In places more enlightened about gun ownership, self-regulation can just happen at the point of a gun, with no need for the middlemen.

> In Libertopia, the only regulations are contract enforcements.

That's disingenuous. There is plenty of libertarian literature on negative externalities. Milton Friedman, notably, was happy to use taxes and regulations to protect the environment.

The reasoning is simple: by polluting my land / poisoning me with PFAS, you have violated the NAP. This kind of pollution is illegal in "Libertopia".

I have polluted your land and poisoned you simply by driving past your window with my combustion engine on my neighboring property. That you draw the line at PFAS is completely arbitrary, which usually becomes clear when you ask libertarians what they believe constitutes an aggression.

Does every single Democrat agree about every minute detail of policy? Expecting unanimous consensus is an unfair bar you only apply to positions you already know you don't like.

The same can be said about your arbitrary argument. Why are the fine schedules set to $X today instead of $X+1? Why do we get drivers licenses at 16 instead of 17? Do you oppose Obamacare because it has such an arbitrary income limit?

Everything about the specific implementation of laws is arbitrary. The important thing is that it is reasonable, and on solid moral ground. A libertarian government would scale the fines / punishment / taxes in accordance with how grevious the crime was.

What is the basis for saying that the kind of pollution you describe is illegal in Libertopia, then? You say that it is, because of NAP. That's a simplistic answer which you now admit isn't necessarily true.

I am exactly not expecting unanimous consensus, which is why statements like "this kind of pollution is illegal in Libertopia [because of NAP]" seem dubious to me.

A fictitious government is always better than a real government for the purposes of argument.