While I'm inclined to stay away from number-heavy systems, I do like what you've put together. I think filling out attributes would be a simple way of clarifying your character's role, strengths, and weaknesses. Personally, I think I'll make Thael's attributes something along the lines of

Commando: 3
Ravager: 8
Sentinel: 18
Synergist: 6
Medic: 0

The idea being that Thael is nigh impossible to take down, but doesn't heal very well. Individual spear thrusts don't do all that much damage, but I want Sunspear to have a real sting to it. I'm thinking I need to add a status effect to Guardian leap, either buffing the ally Thael leaps to or debuffing surrounding enemies to enhance his tank utility, as well as specifying that it provokes enemies.

Since status effects and stagger meters didn't exist when I developed Thael's limit break, I'll need to specify it's function a bit. I'm thinking it would completely empty allied stagger meters and apply all positive status effects for a given period of time, while retaining the "makes enemies run away" aspect.