a spread of 9 turns! That's EXACTLY the kind of thing which creates balance headaches, and why I don't like it.
Correct. 9 turns diference is enough to split an occasional user, and focused master.
9 round cooldown is diferece of a scoundrell with a ring of lightning with a Aerotheurg arch mage.
Where do you see a headeache?
Would you rather allow same cast speed for all?
What is the skill stat for?