I read it in your earlier post, but it didn't really address OP's arguments. It's basically an enforced mediator pattern. Even the article summary points out the language design doesn't provide sufficient security to avoid DOS on the same machine, only for avoiding flooding the network with messages between machines.

As for your solitare example, it goes back to my argument that you're stuck designing both the language and an OS for it, because the problem exists not in the design of the language (grammar, syntax, etc) but in how the runtime interfaces with the host operating system.

No two operating systems have the same semantics or capabilities, and, as I pointed out, even the notion of what defines a file, filesystem or a user is not consistent. You're not going to be embedding those things into the language, but the runtime.