The only way to get true MP is to totally scratch all of the AmigaOS API legacy.
I don't think so. AROS hosted/Linux runs in a single Linux process. You can run multiple instances of it. Even hundreds. Thanks to Linux MP a crash of one instance doesn't affect the others. Of course you would want to add things like GUI (and other) "sharing" so it all looks like one thing.
Something like that. It might be a bit less of a standalone OS then and you might call it AOS environment or framework, but I think it would still not be hugely different to how apps in other OSes "live" where the OS gives the illusion/impression to them that they are the only thing running.
