... and I concluded that his ideas are socialist or maybe anarcho-communist (left-anarchist). They are the same thing, IMO.
Seems like he has never learned about the Tragedy of the Commons.
Take your jet ski example. Would I like to just have it to use and not have to own it? Sure, and so would 50,000 other people. Who will decide who gets to use it when? Who maintains it when it breaks down? Who would buy or make a new one when that one is no longer working?
It's a pipe dream to think that assets can be used by all when nobody has any specific property rights. Either (a) everybody will use existing resources until those resources are used up (Tragedy of the Commons) and nobody will have any self-interest in replacing those resources, or (b) all resources will have to be "allocated" by a central authority (i.e. socialist government).
The first is anarcho-communism (or "pure" communism in the Karl Marx sense) and the second is socialism (in the pseudo-communism sense of the USSR).
These ideas can never work in the real world. Occupy Wall Street type stuff.
So, would I like to use that jet ski without owning it? Sure, and I can do that RIGHT NOW. I go down to the lake, RENT the jet ski from the owner, pay him a fee, and use it for a specific amount of time. The owner maintains it. The owner replaces it when the time comes. And I can use it again the next time I am down at the lake.
Property rights are absolutely necessary in a civilized society, whether minarchist or anarcho-capitalist. My primary takeaway from Peter is that he does not recognize this fundamental fact of reality.