Lazarter, it's going to take practice to be able to get your model's mouth to look and move the way you want it to. You have a good start with your current model but I think your lacking a visual reference such as a rotoscope. Free-handing a human face can be very challenging even for seasoned modelers.
I would suggest snapping a front and side picture of yourself or a friend and importing them into A:M as rotoscopes. From the side view, you can draw a spine outline around edges of the person's face, do the same for the front view, this will give you a better guide to work from as you create your model. From teh front view, draw spline outlines around the eyes and mouth areas. Below is an image of what I'm talking about.
A good key to modeling a human face is to use as use as few splines as possible, this will help create a smooth surface and lessen the amount of work for you when it's time to setup mouth phonemes. Example, in your current image, there are way too many splines concentrated in the mouth region... spread some of those out brother.
Make one spline do maximum work in your model. Create a spline around the mouth in the form of a loop, when you extrude from that loop, A:M creates new splines that do a lot of bending for you... take advantage of that. Hope this helps...