I get the impression the laws they're breaking would relate to vagrancy and trespassing. Also, it seemed like they were trying to locate themselves within walking distance of major cities, so it wasn't like they were holing themselves up in total isolation like the Unabomber or something. Plus, he didn't want to settle. That was part of the point that he continually wanted to move on, and not to stay in one place. I agree there were a lot of questions that remained entirely unanswered though. It fell short in quite a lot of ways I think.

I don't think he didn't wanna settle. They say multiple times they stayed long on that shelter. What he didn't wanna is to live around other people. There's a scene that Tom also say she wished he'd build a house, and the issue is that they don't own any land.

Indeed the movie plot is very far from reality. There are so many homeless people, they earn a big pretty house for free, and they don't like it lol

They could go to some indigenous settlement, they have vast lands, I'm sure they'd allow a couple people to settle on their demarcated lands. Or he could work for somebody who owns a farm. There are a lot of rich people that live in the city and own a farm where they go often, and they pay a family to live there and take care of the land. Then he'd just need to build a small house on the forest far from owner's house, and live there watching the land.