[@Vor]
I knew Sanderson had a Cosmere (Wit ftw, btw!), but I wasn't aware that the same rules applied for magic in all of his series. That's intriguing. 

Also, your proposal is a very interesting idea, and I think it fits pretty seamlessly with what I've already written. I didn't mention it, only alluded to it, but it takes study and practice to be able to become a Sorcerer. Think of how many people in our world are capable of concentrating on one thing, and one thing only. You don't find a lot of people with that level of focus, and so it would require training to be able to do it. 

My idea is that everybody has the potential to become a Sorcerer. It's not a genetic trait, or a "Cosmic Gift" of any kind. It is a part of being human, but the ability to channel Magic isn't innate, but something that needs to be taught. Think of it like a language. Everyone, no matter how intelligent, has the potential to learn any language. Some people may be better at it, and others might be very slow at learning, but everyone still can. It's the same principle with this magic system.

But you can't just learn to speak a language if you aren't capable of, well, speech. Think of "Speech" as being able to "Draw Magic". It isn't something you're born with. You are born with the potential to do it, but you have to learn it first. So once you've learned Speech, you are capable of advancing to learning how to Shape magic (and shape sounds into words). 

This is all a bit confusing, but here it is in a single sentence: You aren't born with the ability to Draw Magic from Cosmos. You have to learn this skill before you can use magic. Anyone can learn it, but no one is born with it. (This way we avoid a Harry Potter scenario where someone is mad at their bully, and inadvertently explodes them into chunks of gory meat)

But when this skill [i]is[/i] learned, we face another issue: If you can't focus well enough, you may end up with... unstable results. 

"I want to light a candle!"
[b]>Re-enacts the Hiroshima Bombing[/b]

[hr]

I hope everything here made sense xP Thank you for your input. 

Also, you are free to make use of this system if you want. I posted it here just because I had to idea for it.