I dont agree with this.
The only reason being is FF have to have the weapon skill to get more damage from the weapon. Yes the damage bonus is where they get most of their damage. But they still have to spend 100 points to get extra damage. Its not much more either for the 100 points.
The Mental Offense gives us a 100% damage increase in magic. Not just ECU, Literally every offensive spell gets a buff from 100 points. Even Healing is effected by it. Its not like we need ECU Mental focus, Necro Mental focus, Spirtism Mental focus. Where foot fighters have to use 100points for each weapon type.
But I guess a better comparison would be aggressive stance. Because that is like our mental offensive. So It takes 100points from each to do more damage, And 100points for each weapon type/magic school. But you also are not forced to take aggressive stance to go do good damage Where as a mage that dose not have Mental Offense you would be shit as fuck with out it.
So if they buffed mental focus to reduce mana usage by 75% that would give every mage the ability to cast just one more fulm/FS
But on paper 75% sounds broken as fuck. But in reality it would only allow me to cast 5 flame strikes before I am low on mana, besides just 4 so that would not really help.
I really hate my one point
If there was some way mages could block/take less physical damage and actually have it be good. Unlike defensive stance that only reduces 3-5 damage. That is not worth 100 points. When u can have around 40 psy and reduce magic damage by 20, and your chances to resist so you only take 9 damage from an out burst and 19 damage on a fulm.
Perhaps There could be a dex mechanic that gives you % chance to "dodge" an attack.
But this would only be balanced if it was only available to mages. Given that they wont be weighed down by heavy armor.
Because if you have a dex fighter with his max speed, heavy armor and now the ability to dodge an attack that would be broken as fuck.
Maybe only make the doge effect take place if the person has less then 7kg of armor on?
The issue here is, and you even said it, the FF has to put points into skills for extra damage. Without mental offense spells are like being slapped by a wet noodle.. Mental Offense actually increases magic damage by 200% at 100. Every spell that does damage goes up, yes but without it you aren't even doing damage like at all. Without skills a FF is still doing decent damage. I have to put points into Mental Offense, Ecumenical, Vitalism, Mana regeneration, etc just to be at a baseline for magic. The issue here is every other playstyle is already at a baseline. The skills you choose and the stats you choose just make you better. Magic is literally nothing without the skills maxed. On top of that you can't just go craft yourself a spell.. you have to go find it randomly from an enemy or buy it from a broker.
The investment in time, money, and skill points that you need to be a mage is insane. I like the idea of needing to find my spells and such but the starting spells at least need tuned up a bit to allow me to even play the game to find said spells. Mages also need some sort of self-defense.. like a shield spell would do wonders.
When it comes down to it just to get to like a comparative baseline with an FF's damage and survivability I already *need* to spend about 500 skill points. Just to get to the point the FF would be at with nothing. The Vitalism skills and Mental Training skills shouldn't be primaries whatsoever. Those should be secondary as they're absolutely required to even be a mage in the first place. An FF definitely doesn't need to spend that much to at least basically wield their weapon and shield.
As for your next part about a dodge, that could easily be implemented by armor weight. Like the lower your armor weight %, and the higher your dex, the higher your chance to dodge an attack. This way a heavy armor character still has some chance to dodge but it'll be drastically lowered. This way they don't feel like they're just left out and to be realistic they would still have some chance to dodge. However a mage wearing robes wouldn't be weighed down and should be able to move around quite easily. This would also tie into what other people have been saying that armor should actually weigh down the character and slow their movement speed.