Peer review - art magic limited by schools


As we’re going to start a new campaign we would like to use art magic. However, I, as the GM, feel that some limits would benefit the system to make it more gritty.

I was considering the following and any expert advice would be much appreciated:

In order to cast any art magic a play must choose a school (no advantage), one could even consider a special trait as affinity within that element.
At the beginning of play each school is separated into five elements: Earth, Wind, Fire, Water and Life.
The physical elements cannot use illusion or mind-hacks and requires their element to be present in all of their actions.
As a baseline “more” of their element, cannot be created.
Life cannot summon a weapon, but can use illusion and mind-stuff.

Within each element you can gain advantage dice by specialising, but then incur a similar obstacle towards other spells outside your specialisation within your element.
Thus a mage specialising in metal, gains +1d when casting spells involving metal, yet incurs a +1ob when trying to use sand.

Depending on the game Bloodmagic could become a school of specialization under life element same with death magic (or an element of it’s own, sort of fallen school).
Aritificing could be a subschool of whatever element was being manipulated and summoning/spirits elements of their own if our story goes there.

Transmorphing quarrels me a bit as I ultamtely would like earth-folk to be able to transform into earth-stuff, but setting the obstacle somewhat obfuscates me.

What do you think? What are the pitfalls? What could be tweaked to make it better?