Dedicated source skills adds unnecessary complexity.
Flat bonus like :
Source point allows cast a spell or action for Zero AP and even a spell on cool down can be cast by a source point.
Its clean, its powerful.
I think the current system need to be made more readable, and such a change in source usage would help.
Interesting concept, but I don't think it's quite the right flavor for source. The skills actually do a pretty good job of making you understand why it's such dangerous magic.
I do think the ability to cast skills that are on cooldown for a cost of health like in shadowrun would be a nice addition, though perhaps only as a talent. I'm talking like, 50% of your health to cast skills that are on cooldown. Probably way to difficult to balance, still, but would be fun.