So as some people already know and a few do not. The primary character's hero title or what he's supposed to be known as historically is "The Soulless One". My questions are as follows.

What are soul gems? Mediums to house souls? Are they crafted by magics or physical materials? If the primary character holds no soul how is he still able to move? Is there a defined difference between a persons soul, spirit, and mind? If the soulless one has no soul doesn't that make him more culpable for control via possession or mind control magics? Can his body be used as a conduit to consume and or house souls? If my dragon-knight character absorbed the soul of a sorcer do you think I'd get to do an in game class change?

Soul gems are what they generally been in ES games- storage. Crafted by magic, out of gems

Souls don't control muscle movement

soul and spirt are usually synonyms, mind is separate, being tied to the brain, rather than amorphous metaphysical 'stuff.' And by stuff, I mean the end product of male cattle digestion.

Probably more susceptible to possession or mind control. But this is unlikely to come up except as cliched story points.

What would you consume a soul with? As for house, not likely. The main quest is about getting yours back, not (or at least hopefully not) gaining Speshul Powahz! from the lack of one.

And finally, no.

1. Soul gems are made by a physical material that can be found/mined from a mineral in Blackreach known as Geode Veins

2. That is a good question; I would like to know what animated a soulless vessel. Unless its only partially soul trapped.

Or the fact that Nirn & Coldharbour are slightly merged is a determining factor. The realm of the harbourer of your soul being partially merged with Nirn can be what sustains your life force; and you're no different than the daedra that have appeared as a result.