And even if they only look at the bottom line, they should realize it is a temporary gain for a long-term loss. The whole thing perpetuates a cycle of crime.
It is unlikely that the average individual is going to be harmed by this advice. Your own personal home is not going to become a squat - you will not return home one day and find people living in it. It actually plays out more like this: a bank forecloses on a house and the owners leave (or the owners simply stay and stop paying). The article did end up drawing a line toward the end between stealing from individuals and stealing from large corporations.
I think it would work. It is kind of a broad question - many states that are bad places work. I don't think that a world governments would be desirable. It seems that it would create a power structure with an incredible potential for abuse. If we are to have governments, it is best that they are small and fragmented. At least this way some may be able to provide a safe haven, or a check on unrestrained power. For example, if a state becomes abusive its people may flee elsewhere. If the entire world were one state you're basically stuck with what you have got. This is already a problem due to immigration laws and borders, but it would be absolute in a single worldwide government. I also feel like there are many communities who might want to live in very different ways. A local community may be able to agree and live in harmony with social rules and mores. But if we tried to apply one standard of law to the entire world I think many people would not be content with laws.