A few suggestions:
Glass Cannon: Maximum AP +4, Start AP +4, Recovery AP +2 and Vitality -25%
Leech: The character heals (damage X 0.25) points with every physical melee or ranged attack
Resistances: Should have a maximum of 75%
Magical skills (Air, ...): Every 3 points of intelligence should reduce the cooldown and not every 2 points
Physical skills (Scoundrel, ...): Should have a cooldown reduction, too, that is based on dexterity or strength
Ranged weapons: Bow 3 AP and not 4, Crossbow 5 AP and not 6
Tenebrium skill: Should be removed and replaced by a talent
I really don't want to make this thread about the numerical mechanics systems; I touched very briefly on GC, but I really didn't want to say any more than that it trivializes content creating boredom, and that a multiplicative bonus probably isn't feasible. Such discussions would inevitably lead to derailing arguments. Instead, I'd like this thread to focus on less numerical aspects of the game, aspects which are frankly more important.
I'd love to hash this stuff out in a different thread, though.
The one thing in that list which isn't very numerical is the Tenbrium ability being replaced by a talent, which definitely seems like the best solution at the moment.