Light has a strong association with magic, as the majority comes from Magnus, and the Magne-Ge are tied to different hues (CYMK). There are also the different forms of magic involving light. You have the lunar magic alongside solar magic, forming a dichotomy. Is light magic? Or is it of magic? Light can be created and destroyed with magic, but then magic can do nearly anything. What about light from more mundane sources? Is light from a torch any different from light from Magnus? Given that vampires can tolerate light from torches, and even light from magical spells, it would seem that light from Magnus is special. A simpler answer lies in the intensity of the light involved, but is that oversimplifying the actual situation?
What is light? The majority comes from Aetherius, but is it of Aetherius? Or is it a result of the mingling of Mundus and Aetherius at their borders?
Tones. Not much is known about them, as far as I can tell; but the Dwemer used them skillfully to manipulate the Earthbones and lesser souls. What do we know of tones? How do tones manipulate the Earthbones, how do change souls? Are tones to souls as tuning forks are to instruments? What other magicks can be practiced with tones, aside from resonating souls? The Animunculi are powered by soul gems, but are they programmed with tones? I recognize that these questions are largely unanswerable.
Finally, I am of the view that souls are one of the most complex parts of the universe. They can be infinitely divided into subgradients, each level introducing new attributes. They can be changed into physical objects (plane(t)s) and materials (Dwemer metals), and most importantly they are the currency of the gods. Souls can be fused (Dovahkiin, Anumidium), and can undergo fission (subgradient). Souls can be recycled as well as created. It seems that they rely on the belief of others and (most importantly) their belief in themselves to maintain their existence, or they evaporate into nothingness. Of course, if there is a stabilizing influence (the belief of others), they can maintain their form much more easily. But given the Aedra, it seems that sacrifice on the believers part is required.
Was part of Lorkhan's trick to get the Aedra to believe in others, at their own expense? Was their belief in the world, in Nirn, them cutting off pieces of themselves to build it? What about Satakal? Nirn was built from his shedded skins, too. At least according to the Yokudan creation myth. What do those stand for?
Lastly, since the forms developed from subgradients are so interesting, what unseen forms can be seen with the fusion of different pieces?
Any commentary on these thoughts of a madman would be appreciated.