Contra Metaphysical Idealism

[JuliaL]

I see your claim as the universe only exist because we "process it". does that sum it up?

No. What you just said has absolutely zero to do with anything I've ever said. In fact, I've contradicted this idea, which is an extension of solipsism, at least twice.

My claim is that the universe itself is not a collection of things, but of the interrelationships between properties that don't supervene on anything-- i.e. they are just ideas or concepts, and there are no "things" that cause them. But they are not ideas or concepts of people-- they are self-existent ideas or concepts.

Can I play too?

I'll grant that I only experience my experiences.
The universe outside of my immediate vicinity may not exist.
However, I find it simpler to model reality as a collection independent physical things which exist whether I'm observing them or not.
Otherwise I cannot explain the consistency of their behavior. Every time I step outside, my street looks the same. What those materials 'ARE' is unavailable to me. Calling them ideas is no more helpful than calling them fields, relationships of particles or blahverts when their essential nature cannot be known.
If all is ideas thought by myself and others, how do we coordinate our experiences? Universal unconscious ideation? How does THAT work?
You'd still have the problem of determining that the universe created by the minds of others is of the same idea stuff as your own experiences. As others have pointed out, pulling everything into yourself is solipsism. No answer there. At least none that won't be laughed at.

It seems trivially likely based on study of neural pathology and the effects of psychotropic drugs that personal experience is an emergent phenomenon of complicated chemical reactions. The claim that qualia are idiosyncratic and opaque to investigation is under attack.
Creating a self aware neural network is simple. Point the inputs at the network and teach it that when it sees its own pattern, it has recognized itself. Once a self aware network is created, it should be highly preserved by natural selection as self preservation becomes much easier once self is recognized.
A parallel approach to Koch's postulates for identifying infectious organisms can be applied to consciousness. If an experience can be identified as a neurological pattern and transferred from individual to individual, then the experience can be considered identical to the pattern. This is currently being done with memory.
False Memory implantation in mice