In regard to this topic, I have to ask: Have you noticed a special version of DO geared toward the immaterial beings (remember link #4, nama-rupa)? So far I haven't, but I admit that my reading is incomplete, and I'm not a scholarly sort.
I asked Ven Dhammanando about this once on E-sangha and he actually said that yes, there is a D.O. for formless beings - and in their case it only involves nama and not rupa. This can not be found in the Suttas but I assume it's a perspective adapted from Abhidhamma.
But I have noticed that humans can experience the immaterial realm by the development of different modes of perception (see MN 121), so those experiences are not limited only to the beings existent in these realms. In terms of what humans are composed of, the Buddha described rupa in terms of the four great elements, which is a concise way to view experience (as solid, liquid, energy, motion), but is far incomplete in terms of modern physics. But still, the applications of that understanding is quite great. As is the list of 31 parts, which is far short of the total parts in the body understood in modern biology. Again, as has been pointed out on this forum time and time again, the Buddha was master of the similie and instruction, and may have been less concerned with imparting to us a flawless understanding of the mechanics involved.
As physical science, the four elements are a primitive understanding, but as you indicate the Buddha was not trying to impart a scientific understanding. The four elements are still quite useful in terms of understanding the dhamma, and they serve as appropriate objects of meditation and for developing a perception of anatta.
My point is this: the distinction between the three realms may be more a matter of short hand rather than an absolute reflection of reality. Perphaps each realm is labeled more in terms of the primary mode of perception rather than the matter-energy that it is formed from. The actual manner that an immaterial being forms and is maintained, let alone functions, is not spelled out in the canon.
Yes, it's not really the kind of thing the Buddha spent a lot of time on, but that's primarily because there isn't a whole lot of use for such realms with regards to liberation. Remember that the Buddha's first two meditation teachers attained formless states of meditation - and that the Buddha left these teachers becuase "'This Dhamma leads not to disenchantment, to dispassion, to cessation, to stilling, to direct knowledge, to Awakening, nor to Unbinding, but only to reappearance in the dimension of nothingness... reappearance in the dimension of nothingness..."
My understanding is that one attains these meditative states, passes away while in them, and then reappears in these planes. One spents a few jillion years there only to take reappearance again in some other realm (back in the human realm with a 9 - 5 job, as Bhikkhu Bodhi once pointed out).
And neither is the full nature of consciousness. While it seems necessitated by rebirth that consciousness is not dependent on a specific beings existence, it is not necessitated by rebirth that consciousness is completely independent of all the universe and the laws therein.
Depends on which laws you mean! Since materiality is non-physical, physical laws do not apply, newtonian, quantum, string, whatever. All physical laws do is describe what happens in the world of materiality. If by law you mean dhamma, then nothing is exempt.
I have to ask, though: if the immaterial realm is really immaterial, then what is it constituted by, if you rule out both matter and energy? And if neither matter nor energy are there, by what means does cause and effect operate?
I think cause and effect operate by means of cause and effect. I don't see a need for anything else.