I really think that that some things could change in the defense and damage calculations formulae’s:
1: All Skills being MAG damage, this simply is not working too well. If the damage was ATK (physical) I think that the nerf would not even be necessary, as many would be able to build some good rangers to take down mystics, but since Lulu's event i noticed tha using a skill with a ranger is only worth because of the added utility, like status infliction. A regular attack from a ranger almost always will do more damage to any enemy in the game, it's just broken. We charge the skill for 4-6 turns and do MAG type of damage to a mystic that, of course will have a very high MAG status...
Before someone say that we need MAG Def, not, we don't need this, as I think that having only one MAG status was perfect for the game, simply because of the faith and skill system. We only take MAG damage in between 3-5 turns depending on the enemy, so an MAG def status would only complicate things even more.
2: The MAG status of all heroes and valiant. Yeah, some did had numbers so low that it was the cause to them dying with only one hit. A guardian should have a high MAG status, as a tank needs to take mag damage, as it's the only class in the game capable of tanking.
3: Damage calculation on multi physical attacks. You use the attack of a Mystic that have a plus area (+) being only the central of the plus (+) 100% damage, and the other areas doing 30% damage, only that is not doing that, as the damage penalty of 70% is being added at the beginning of the formula, so, the central enemy takes 1000 points of damage, while the others are takin less than 100 points. Why? I should be 300!
4: All skills of a class being based on a single status: Why is that? We take two routes in the class system, and when they diverge in the 4* path the skills continues to be based on the same status, if by example we had between the 4 possible end jobs two different Status based Skills, that would lessen the frustration in getting a hero with the wrong aura. Making by Example the Chaos Knight (job have high native ATK status) have a skill based on Attack, and Paladin based on DEF (job have high native DEF status). We can go further and split some jobs in the Hunter class that will do magical damage and physical damage, so we can use as we see fit against the circumstances and the enemy.
I know it may seem like a rant but it's not, this game is awesome even the way it is right now, but I know it can definitely get even better.