Just another way of saying, "God created the universe ex nihilo". Substitute "God" for someone, and you have Bishop Berkeley's position. Which, I point out, is, a few near-meaningless fluff words notwithstanding, identical to your position.
Contrary to your contention, there is no way to physically demonstrate that the universe is not the product of some overheated imagination, any more than it is possible to physically demonstrate that God didn't whop up the universe out of nothing. Both are immaterial ontological conjectures beyond the competence of material beings to either confirm or deny.
The two are certainly not equally reasonable. I think the preponderance of logical reasoning coupled with sensory perception tend to tilt the balance in favor of a real universe, don't you?
That aside, I do not see any conflict between God thinking up the universe in his imagination and the ordered complex universe we have today as long as we believe it is all real and can function well within it (which we can). How is one antithetical to the other in the practical sense?
But what if matter is an illusion? Do our senses lie to us? If this all just one big "Matrix"? (I think you watch too many movies. ) In my mind, illusion is akin to mirage or chimera or phantom. Is that your definition? Conversely, matter is real - you can touch it, see it, hear it and feel it, and when you manipulate it, it performs in an ordered and expected manner according to natural laws - it does not surprise us or behave like a phantom - it is consistent and perpetual. But what if the matter we see is real to us, but in reality, is an illusion - so what! - there is no practical difference from our perspective. Even if God did produce the universe as a collosal illusion, from our perspective it is real! Even if it is true that the universe is an illusion, someone must create an illusion since there are no known ways for such complex and ordered illusions as ours to just create and maintain themselves.
Finally, what reason do you have for believing that a mirage could produce such empirical results? I must deny my senses to believe all is an illusion, and, as a rational person, I must conclude from my 5 senses that the universe is real and is not an illusion. Mustn't you also? No honest naturalist would agree with you that the two theories (illusion vs. real universe) are equally valid, especially since empiricism and logical positivism demand that matter be real not an illusion.
There is no way for a naturalist to demonstrate that the universe simply "exploded" from NOTHING, and that the result was the fantastic complexity and mind-boggling order we we have before us today. But that is precisely what most naturalists believe. Logically, nothing cannot produce anything because by definition, it is nothing. That is much more of a leap in my view than my believing that ordered complexity on the scale we have must have come from a creator. I must conclude that you have no view whatsoever on the origins of the universe, because regardless of what view you might hold, it would be a leap - wouldn't it?