Style is totally trustworthy; you couldn't get rid of your style even if you tried. So, as you look at news ways to do things, don't worry about losing what you already value about your work. If anything, more ability will let you hew closer to the authentic personality that your style communicates.
The answers here are all correct: drawing is simply the basics, over and over again until you perfect them. There's no higher level teaching that you get to when you are super awesome, just a deeper, more subtle understanding of those same basics. Here's my short list of essential skills:
Perspective: Linear, Proportional, Foreshortening, Point of View control
Anatomy: Human Structure, Movement Dynamics
Acting: Facial Expressions, Body Language, Choice of Moment
Color: Color Theory, Light and Shadow
That's it; doing those things well is basically all there is to it. 