You could definitely use the word "superimposed" and yes, the "higher levels" remain in existence even if the "lower" ones don't manifest. But only as potentials that may or may not manifest according to "superimposed" natural rules.

Those examples I mentioned (Buddhism, Kabbalah) are pretty much in line with how the observer is theorized to collapse the wave function -- when no one lives in (observes) a particular realm, that realm does not exist (yet it still exists, as a distinct possibility). Something along the lines of that optical illusion with cup vs. two faces while the reality is simply "a picture". Or paraphrasing the words of New Testament, God is the God of living not dead because to God everything that is continues to be, which is also in line with how e.g. Abraham is still "alive" because the consequences of his manifestation lead the world to its present state (and that is true for all manifestations, no matter how "insignificant"). Though that Biblical example is from the vantage point of present to past.

Now all of that would imply that the whole created universe is basically "God's mind" and we are really "created in his image" as thoughts of minds arising in, and made conscious by, consciousness which in turn is identical throughout the whole spectrum ("I am that I am"; "This Atman is Brahman"; "I and the Father are one"; etc.). No wonder that the whole experience resembles a simulation (essentially a quantum computer) and humanity is obsessed with creating their own simulated "sub-universes", even though we already create them in our minds (together with autonomous avatars). Truly, as above, so below.

However, that also begs the question that if God is omniscient, separate from us, and we are obviously "created in his image" (at least at the level of consciousness) how is it possible that we can still observe e.g. slit experiment? After all, the universe as a whole would be already observed and all waves would be already collapsed, or God would not be omniscient, etc.

But if God is simply consciousness / existence it all makes perfect sense. That however also means that there's no personal afterlife as it is traditionally understood, and reincarnation simply means perpetuation of certain behavioral patterns. That is to say, "creating" people who will have to struggle with errors of the ones who came before and caused them to adopt the same erroneous behavior -- voila "past-life" karma. And being able to remember the people who caused our karma is simply within the possibilities of human mind as each of us is a tip of a particular causal stream).