Sort of. With the salient point that nothing really exists, but the commons. The individual is nothing without the whole society around.

Also sort of. Some form of social organization seems to be necessary for humans to function. But humans are also pretty good (well - relatively speaking, it usually seems to require a war or revolution) at changing that form of social organization as technology, population, and environmental conditions change.

I think this is a very likely outcome. We aren't going to get continued population growth next generation; a significant number of the people needed for it will never be born. This is going to have ripple effects across wide swaths of political and economic organization. But you'll have pockets of population that basically barricade themselves off from the wider economic world and insulate themselves from its collapse, and then the people within them, along with whatever form of social organization they happen to adopt.