Matter, Psyche & Spirit are simply different wavelengths of existence.
Wavelengths, huh? Okay then, what wavelengths are they specifically? Even a rough estimate of the range would be something. 650-719nm for matter, 720-949nm for psyche and 950-1103nm for spirit? How do these wavelengths define their properties? How does amplitude and velocity figure into things? What exactly occupies the wavelengths not taken up by matter, psyche and/or spirit? Most importantly, what kind of waves are we talking about in the first place? And don't even think about saying it's "quantum" related. I can assure you that quantum wavelengths have absolutely nothing to do any of... This sort of thing.
Matter is super-dense, subject to laws of death, decay, corruption, impermanence, imperfection.
How exactly does corruption and imperfection apply to anything non-man-made? For starters, both, perfection in particular, are subjective qualifiers. Some people may consider a certain movie, book, piece of furniture or a meal to be perfect or as near perfect as it get, while the next person may find the same things outright repulsive. As for corruption, well, that's about as human-specific, particular modern human, as it gets. Trying to apply that to anything not related to humans is rather silly. For example, what qualifies, say, a rock, or a planet, or a hexane molecule, as corrupt/imperfect or not?
Spirit, however, is the exact opposite of these qualities & is eternal.
So you're essentially implying that "spirit" is not subject to entropy, no? Considering entropy is a rather fundamental law of physics, that's a rather massive claim you're making. Especially as merely a different wavelength (wavelength of what, you've yet to define) is all that's needed to violate what all evidence and scientific understanding so far has supported being fundamental law.
Psyche/Mind/Astral is in between these two things and is also a sort of link/doorway between the two. There's different levels of Astral, to the mundane everyday thoughts/imagination/daydreams or other levels such as the dream level, followed by something somewhat akin to the Spirit plane.
While not quite as huge as "entropy doesn't apply", here you're basically claiming that our understanding of neuroscience and specifically information theory is false. That thoughts and dreams are not fact a conscious interpretation of various chemical and electrical signals within the brain but rather something (which you've only very vaguely defined) completely different.
Now sure, you could say that this is just your "personal spirituality" or some such (i.e. Honestly, you know deep down that the world does not in fact work that way and you are not in fact in any sort of position to refute the collective works of thousands of scientists who actually study this sort of thing and back their claims up with real proof, but it's fun to play make-believe). However, you also said this.
The idea of "The Big Guy In The Sky" or variations thereof is a bunch of unscientific, unprovable, superstitious, primitive claptrap.
Unless this was a completely unrelated observation, you seem to be implying that your own beliefs are not in fact unscientific or superstitious. If that's the case, then the "spirituality" defense is simply not going to fly. If something is to be scientifically sound, it needs actual proof to back it up. If it goes against even an existing theory, much less an entire field of science and even a fundamental law of physics, then you're going to need some really fucking serious evidence to both back your own claims and to disprove what you're contradicting. Evidence that, assuming it hypothetically exists, would most likely take multiple qualified teams of scientists (I'm talking doctorate level education and access to all the funding and equipment that they need) decades to discover and satisfactorily test, at the very least. I'm guessing that your scientific education doesn't even go beyond high school, if that. If you can't make with this kind of proof (and let's be honest, it's not going to happen), then your beliefs are just as unscientific, superstitious, moronic and outright false as any traditional theists'. Not only that, but the sheer delusional arrogance that you're anywhere near the same level as real physicists and neurologists is just astounding, though to be fair that does indeed apply to fundies of any flavour.