Righteeho, had a quick peek and it looks pretty good so far - the basic proportions are okay to begin with, that's the major thing to get correct right off. The cranium might do with being a little deeper front to back, but that varies quite a bit on different people.
Two specific things I notice are the jaw looks like it has rotated in order to open and the cheekbones have become more prominent because of the hollowing of cheek area - both key things that happen when this expression is made and important to try to capture if you're aiming for realism. One of the other main things to strive for now is correctly capturing the shape at the bottom-rear of the jaw, just under where the ears will go.
You mention the eyes need some work but rather than suggesting redoing them completely, I'd recommend for future projects doing them as additions on top of a blank eye area, or even a shallow depression made with a ball tool (either method can work well, depending on the face). This will help prevent certain common issues essentially caused by there being too much pliable putty underneath where detail is being formed.
I recommend this general principle more widely for faces done in MS and similar hardening compounds, which takes advantage of the setting to allow the basic structure to be laid down, then the detail formed on top (much like flesh laid on top of bone) in stages without disturbing the basic shaping done previously.
Einion