To the previous post:
Pretty much, yeah. My original advice was to be fluent in many theories (regardless which ones), so that you can expand your expression specifically where expansion is necessary, sometimes extreme, sometimes minute. The main idea was that certain expressions could be achieved by bridging multiple musical languages, in which some rules would be changed, some styles may be changed, etc. Using this technique, by altering parts of the musical space you have at your will (and like you said, given the talent, doing it with skill), you can express pretty much anything you want to.
The greatest thing about multiple music theories is that the conglomeration of which can be immensely useful, and you're not so much breaking rules as you are changing, re-writing, or combining them, to the point that "correction" is very personal to the writer. And to do these thing with both expression AND skill... well, if you could, you'd be a frikkin music GOD.