> Just one regarding the CS. Soul appearance. Is this something everyone fills out or just the Meisters?

Soul is for all races and both Meister and Weapon. Souls all have different colors, designs and so on. Most Meisters generally have the ability to tell what a soul looks like and how powerful it is. When partners are formed, it is generally due to whether or not they can "resonate". Should a soul resonate, they would be able to use their partner in an extra special way -- "Soul Resonance". 

Think of it like your final smash.