I have been reading "Gnosticism" and it seemed to be completely weird since my paradigm was that of doxa. I was scoffing: "I am expected to believe in a lion-headed god who has sufficient understanding to organize worlds and yet does not ask where he/it comes from?" Even humans ask that question. Now understanding that the myth is illustrative, not realistic, accurate, but not precise, has put a whole new face on it.
Seeing myths as literal is how the heresiologists completely misunderstood the Gnostic approach. Ireneaus has endless scorn for myths that he viewed with a physical literalism. And, such an approach would make for a very weird if not downright kooky religion. (Of which there are a few contemporary examples, unfortunately.)
Even though we have only a smattering of ancient Gnostic materials, we have examples of exegesis (commentary) on the Gospel of John by Heracleon. From quotes preserved by a later commenter, we can see that for Heracleon there were three ways to consider scripture: physical, psychological, and spiritual. The physical, or historical, approach was considered the least useful if not actually misleading, and this was the relatively straight-forward story of the Gospel of John taken by many people today to be the literal historical truth. He saw the spiritual meaning of the Gospel as being a means to liberation. As essentially being realized within the spiritual development of the seeking reader. So, there is a strong tradition of viewing myths/stories as tools for gaining insight or moving towards Gnosis, rather than statements of fact or literal/physical histories.
Not only can we consider myths on multiple levels, we are not stuck with a single interpretation or understanding. So, the demiurge can be seen in the contradictions of the cosmos, in the limitations and grandiosity of the human ego, as the way of understanding the limitations placed on a "God" by most believers, as a way to separate the notion of a God-image from the experience of the divine, as a pattern of human development, and so on. The element of divided or compartmentalized consciousness you've described is a part of that. It is a pattern that aids in recognition or diagnosis, a tool for developing Gnosis. With that Gnosis, we can then recognize it in different contexts, leading to a growth of insight into the original descriptions as well as into the contexts. 'Recognition' being a common translation of gnosis.
Can myths mean anything at all? There must, in the end, taken to a logical (or even illogical) conclusion, by analysis, by synthesis, by any systematic way, be a real truth.
Heraclitus wrote of the tendency to "run to the opposite,” enantiodromia in Greek. (I don't think it was the opposite he frowned upon so much as the haste.) It isn't the case that myth has to either mean one thing or mean anything and nothing. Looking at it that way evades the meaning of myth itself. Rather than seeking one meaning, or any meaning, it is more useful to consider it as a pattern with many applications.
A deep understanding can be expressed as a myth, as a story, and we can learn from the deeper lessons than merely learning the story itself. This is the value of literature, for example. We experience King Lear not so we can take a quiz on its contents, but so we can understand something about ourselves, and also our world.
To say that something has many applications, or even innumerable/infinite ones, is not to say that it can have any meaning. An example of this is number. We can apply number to any type of thing by counting whatever it is. Yet, regardless of what it is we are counting, from the concrete to the abstract, the application of numbers and of arithmetic will apply in an entirely non-arbitrary way. Because we can count literally anything doesn't mean that the numbers mean anything or nothing. They remain the same regardless.
It is this type of insight into numbers and their relationships that was at the core of the Pythagorean tradition. Numbers were the archetypes, or "primal shapes/patterns" of the system of the world. It is a bit hard to get to the profundity of that with our modern minds. We think of numbers as the most rational of our tools, and they often are. We are also usually presented them in an abstract way, as a system of rules. But looking at the world itself and seeing the universal application and validity of these patterns of numbers and their relationships is amazing. It is a leap from the particular to the universal. Newton could have accounted for the level of mechanics he was working on with a limited theory of gravitation, but he saw it not as a way to account for forces, but as a part of the order of the cosmos, and his theory of gravitation was a universal one.
One shouldn't "run to the opposite" here either. (A gentle stroll gives a better view.) Jumping from a particular to a universal is a really big jump and in general is just not recommended. Describing mythic patterns in this deeper sense is a part of what the ancient Gnostics were doing with their myth-making. Gnosis is that type of knowledge, we can translate it as recognition or acquaintanceship. A knowledge of such things as these patterns. Though not limited to them. That type of knowledge can only be transmitted indirectly through story and symbol. So that, becoming familiar with the story or symbol might help to recognize that pattern in our own experience.