Things exist. Cars, buses and dogs exist. But I know a car when I see one; a bus and dog too. If each one shares the property of existence, why does the mind see differences in perception. Is it solely the mind that perceive these differences?
In the materialist view, both the mind/consciousness and object(s) of mind exist as energy/atomic realities. If the mind is supreme then physical reality cannot exist with out the mind. It is subject to the supreme mind. If mind is limited then it cannot create physical objects nor ultimately affect physical objects. It can be overwhelmed by physical reality.
Mindless objects, like a tennis racquet, cannot perceive themselves, so logically only a "mind" can perceive an object. An object is an object is an object. In my thinking, a soulless object, like a rock, might as well not exist, because with out a the mind what is the purpose of a rock? does it have a purpose?
The mind/consciousness is the awareness of itself and others. some inner "qualia", like a person waking up in a field and perceiving the sky, sun and clouds. Sleeping cannot see anything, the mind is "off". The mind is taking a break. When the mind is "off", "nothing" can be perceived; if anything, very limited. what is the purpose of a mind without an object of the mind?
We first need to tease out several assumptions that underlie your questions. The first is that there are (at least...) two kinds of "stuff" in the universe -- mind and matter. Most modern philosophers disagree. The current dogma is that we should use "methodological naturalism" -- assume that there is only matter (convertible to energy) and that we should use explanations (including entities needed to make the explanation work) only when a naturalistic (= materialist) explanation is impossible. (Ideally, the "impossibility" should be of a logical nature, a demonstration that the materialist explanation cannot make sense for logical reasons.)
That aside, you also assume that there is some kind of hierarchy of "stuff" that makes mind supreme. Even if that were true and mind ranked matter, it does not follow that matter cannot exist without mind. Nor does it follow that there is a hierarchy of mind with one supreme mind at the top. (On the materialist side, there is no "supreme proton" -- there is a vast number of them, and none of them ranks any other.) The same could be true of minds.
Material "stuff" doesn't need to have purposes. "Purpose" is a concept that has meaning only within a language, or, as Wittgenstein put it, a "form of life." Only a culture with the concept of purpose can ask the question about the purpose of a rock; the rock never worries about it.
Finally, you seem to have some version of Bishop Berkeley's theory of ideas behind your questions -- his basic idea being that since we could explain all relationships between mental states/objects in terms of mental states/objects, there is no need to postulate an external, material world at all. In his universe, there is only mind, not matter.
It's very hard to come up with a philosophical theory that postulates more than one kind of fundamental "stuff" without running into major problems. The one that comes up first is explaining the interaction between the kinds. And your question addresses that -- if mind and matter both exists, how do they interact? Most modern philosophers would say that's an unanswerable question unless we have a fuller account of the properties of each.
You may also have, from quantum physics, the idea that things don't have definite properties until they are observed. They exist in all possible states until a "mind" looks at them, then the "wave function" collapses and they become "real' as one definite thing. Most philosophers and physicists are uncomfortable with this idea, but it seems to be a real feature of the material world and is being exploited to build quantum computers.
In sum, we need to resolve these issues before answers to your questions would make sense. We need to resolve whether or not there are two kinds of "stuff" and whether or not there are hierarchies within them to start producing answers.
You may find these two references interesting:
Hope this helps.