A problem for this interpretation is that the necessary cosmology, astrophysics, geology and evolution would have to be dependent on future observation, even though consciousness depends on having bodies that evolved because of those conditions being met. — Marchesk

I realize this is the main problem with this interpretation. I can see two possible solutions:

a) The laws of physics are fixed and eternal. Consciousness is fundamental, and has been there since the Big Bang (this would look quite similar to the traditional idea of God, I'm afraid).

b) Consciousness and the laws of physics (the laws of observation) have evolved at the same time. The laws of physcis are not fixed, they are more like habits (like in Rupert Sheldrake's view of evolution). We can imagine that the first observation started with a small bacterium, capable of distinguishing between light and dark, wet and dry, warm and cold (this is pure Taoism). In this vision, consciousness is a property of living organisms. This notion would imply that it is incorrect to try to project the current laws of physics into the past: they only can make predictions about the future. In other words, there was never a Big Bang. There were no oceans until the first bacteria appeared. The stars we can see now only came into existence when the first animals that evolved eyes observed them, etc.

I personally find option b the most likely, although it certainly feels weird and quite difficult to imagine. But the materialistic narrative is literally impossible to imagine: can anyone imagine a Big Bang without anybody looking at it? By definition, the answer is no. You need to imagine yourself looking at it (from the perspective of "God", I guess) to be able to imagine it. But that's cheating.

Thanks for your answer!
The whole point of my "idealistic interpretation" is to see if we can account for everything we know about the "physical world" without the assumption that it exists outside observation. My contention is that we can. Therefore, following Occam's razor, we should let go of that assumption, especially since doing so all the problems and paradoxes of quantum mechanics seem to go away.
I'm not denying that you can also give account of the universe by assuming that it exists independently of any observer, but that wasn't my point. :)

Sounds like a great idea! I also have thought for many years about writing a fantasy or sci-fi novel that could have on readers the kind of impact that The Matrix film had. So I say, go for it!
Here is my piece of advice:

1. Start thinking about a plot that would illustrate your philosophical ideas: these ideas should be showed in the actual plot, not just expressed by the characters in the dialogue (although a few good hints in the dialogue can obviously help). The Matrix is a perfect example of this: it has terrible dialogue, but a spectacular and mind-blowing plot. That's where its power resides.
Thinking out this plot is the most difficult and crucial part of creating your novel. But it can also be the most fascinating and rewarding.

2. Once you have a good plot that fleshes out your philosophical ideas (or your philosophical questions, which would be even better), you need good characters. Characters that your readers will care about. The most amazing plot will fall flat if your characters aren't up to the task. Remember that you are writing a novel, not a movie script. You can't rely on the carisma of some famous actor like Keanu Reeves (an absolute star, imho). There are many books that teach you how to "flesh out" your characters, but in the end I feel it all comes down to having a deep understanding of human psychology, and that can only start with understanding yourself. Deeply.

3. And this takes me to the discussion about the classics of literature: Cervantes, Tolstoy, Dostoevsky... These are classics because of the depth of their characters. (Other classics like Hemingway or James Joyce are more so because of the quality of their narrative voice, but I won't go there now.) And they are never boring. I just read Dostoevsky's The Idiot and boy, was that a page-turner! More addictive than any stupid best-seller I ever read (I also read some of those, yes). There have been famous books like Thomas Mann's The Magic Mountain that consist almost exclusively of interminable philosophical dialogues (or sometimes monologues), but that's not what you want: those kind of books are the definition of "boring" for an average reader. So again, I recommend you express your philosophy through the action and the interactions between the characters, not the dialogue.

4. Some writers that have tried this kind of thing (expressing philosophical ideas through popular fantasy or sci-fi novels): George Orwell, Aldous Huxley, Colin Wilson, Ursula K. Le Guin, Frank Herbert, Philip K. Dick... the list is endless. Actually, most great sci-fi writers ground their works on deep philosophical questions. Outside sci-fi you have writers like Hermann Hesse... There must be others, but they don't come to my mind right now. I think most philosophically minded novelists have always tended towards science-fiction or fantasy. An early example is Jonathan Swift's Gulliver's Travels.

Anyway, I hope this helps! Even if you never get to publish or even finish your novel you will have great fun and learn a lot, I guarantee. I just finished my "masterpiece", which is exactly like that, a "The Matrix"-like work of fiction, and I'm feeling pretty happy and proud of my achievement. :)

Very interesting discussion! I personally think that idealism is the most viable philosophical view, since it seems to be supported by the findings of quantum physics (although most physicists refuse to admit this inconvenient fact). I just started a new discussion on this topic, under the title "Idealistic interpretation of quantum mechanics".