A problem of the magic system that can be annoying is that, mastery of a more complex form of magic is entirely independent of the more fundamental skill. A character can sink 1cp on ignite, shape fire, and create fire, and 20 on fireball.
there is a simple solution to this, and its been done before in the game system. If certain spells are skills, why not go all the way and apply technique sub-system to it. Begin a specific Thaumaturgical Discipline, partiuclar to a school of magic. The most basic spells there after are Hard techniques that default -4 or -6 (if VH) to this skill with the same non-spell prerequisites. Every more advance spell, defaults -4 or -6 to the technique it requires.
Consider 35 points:
- IQ12; DX10; Magery (Fire) 0 (5)
- Thaumaturgy (Fire School of Magic) (VH) IQ+3 -15
- Ignite (Hard; Default Thaumaturgy: Fire School+0) -15
- Shape Fire (Hard; Default Ignite -4) [1*]-11
- Create Fire (Hard; Default Ignite -3) -12
- Fire Ball (Hard; Default the Average of Create and Shape Fire -4) [1*]-7!
- Spell Throwing (E) DX -10
*because hard techniques require 2 points to budge the default modifier. Consider 1cp a 0 modifier budget that gives the character the ability to perform the feat.
Notice that more complex spells cannot be better than the fundamental techniques. if Mr. fire wants to master Fireball, he has to master the Thaumaturgical school and all the basic techniques first.
Combine this with the:
x6 (I think I might go with x5 time modifier on ALL spells)
and the Takes Extra time and Haste Rules.
I prefer my system compared to this (35points)
- IQ12; DX10; Magery (Fire) 0 
- Thaumaturgy (VH) IQ-3 -9
- Ignite (H) IQ-2 -10
- Shape Fire (H) IQ-2 -10
- Create Fire (H) IQ-2 -10
- Fire Ball (H) IQ+5 -17!
- Spell Throwing (E) DX+1 -11
I do admit its a bit easier to min max, but