Hey madrar, I've been rereading your "Triad" theory. It is so well crafted, good job! I was preoccupied with trying to pin down the characters of the Elvhen Pantheon for such a long time, I wasn't interested in moving on to whatever existed before. But I realise now that your triad fits neatly with everything we've discovered/tin-foil hatted so far. The Songs and the nature of magic in particular. I AM ON BOARD!
until DLC evidences otherwise
So I can answer my own questions in my last post with the triad! Wham, bam, thank you ma'am.
WELCOME TO NUTJOBVILLE! @w@ Pay no attention to the unnecessarily complicated version, though. I wrote all that up before realizing the writers had been hitting us over the head with the key the whole time. The "fade" of the game world and our reality share basic laws that are bent, but never broken. Realizing that would have made explaining the rest so much simpler.
Triad Magic is Nuclear Fission.

Ta da! The Wife and Husband are the bonded nucleus. The Lover is the free neutron. Like all fission, the split releases a truly absurd amount of power, which produces drastic change. Potentially catastrophic results and toxic aftermath are the obvious thematic bonus.
Creation Magic is Biological Fusion.
All life on Thedas, and even the planet itself, comes from Fusion. The merging of Sun and Earth. Physical and Fade. And if you want to get disturbingly literal with the imagery of the Sun "dragon" and the Earth....

...there you go. @w@
Generic Magic is Combustion.
The most obvious in-game demonstration of this theory in practice is Mythal, but there's reason to believe it might be the underlying nature of all "everyday" magic with respect to the Stone (Thedas). Like Creation magic, it's the intersection of Physical and Fade- but like Triad magic, the fade component is consumed by its use. It is Earth and Sun as Coal and Fire.

The combination burns, producing power at a cost: a measure of Earth is irrecoverably lost. Again, I'm still uncertain whether this holds true with generic magic's Fade component, which from a certain perspective would be the Stone's literal "soul". Need more data. The inferred environmental / conservationist subtext wouldn't be too out of place- this is Bioware, not Rockstar North. Also the steady leeching of a finite magic reserve leading toward conditions of modern Earth supports the "worthy struggle" theme. Mage-style magic is still too easy as a means of Change, just as Eden was too easy. Difficulty is what makes change meaningful, worthwhile, lasting, etc, etc.
This, though, is why Mythal's orb looks like it was crafted from Anthracite Coal, as does the shell of her physical body after transferring the last of her power to Solas. (The bright blue flame graphic is a telling hint.) Her immortal OGS remains to be transferred to Morrigan, but the reserve of ancient Fade she carried into this world (the remains of her soul, her power) is completely spent. Once Solas uses that flame, there is no more.
Choice Magic is Sustainable Energy.

Like the others, the intersection of Earth and Sun (Option and Will) grants the wielder a degree of power over the world around her. It might not be as easy or flashy as "combustion" magic above, but (critically) it's universal and infinite, granting every sentient being the ability to change the world... both in game and out. (Assuming a critical degree of social balance is maintained to make Choice both possible and meaningful. Cue Solas.)
And of course, all of this ties into the Song at every level. @w@ Quantum harmonic oscillators at the atomic, DNA at the biological, player Choices as individual notes in the Song of Creation that defines their Thedas in the grand overview...
...now if I could just figure out how elvhen inheritance makes sense. (ᕤ≧w≦)ᕤ