Depends on what you mean exactly. In many countries including the USA there is land that's not owned by any private person, but the state. Not claimed by any entity is https://en.wikipedia.org/wiki/Terra_nullius
Same thing, effectively. Funny enough that land was grabbed back in the 1600's based on very flimsy rhetoric about how just claiming land for yourself was a god given right for all human beings and that it would solve all problems by free market principles (which were not yet formalized but would soon be, specifically based on said rhetoric).
We were fucked by hobby philosophers hundreds of years ago. Don't come tell me a philosophy degree is worthless.
Those are called sophists. Today we'd call them lawyers. Or Republicans.
The Sophists were more concerned with being able to convince others that a particular opinion was to be believed, even when they knew it was actually false. Whereas Socrates was concerned only with the truth, even when it wasn't something he wanted to be true.
...presuming you've asked them to leave and they've responded by threatening force or using force against you, and assuming that bill actually passes, yes.
Sounds cool in some utopian parallel universe, but as long as there are people willing to take advantage of others it's not going to work in the real world. Imagine putting a lot of work in your garden and some random crazy person puts up a camping tent in it because they don't believe in private property? Just get out in 5 minutes or I'll call the cops.
Not quite. Based on what that bill actually says, it's not legal to shoot you for "unlawful camping" unless they ask you to leave and you respond by threatening violence against them or actually engaging in violence against them.