A common technique to make your model appear more clay-like is to use Ambient Occlusion.
You have to turn this on in two different places.
In the Choreography properties, under Global Ambiance Type, set "Ambiance Occlusion" to something (try 100% for starters).
In the Camera Properties, under Render Options, set Ambiance Occlusion to ON
Also in the Camera Properties, under Render Options, set Multi-Pass to ON. You can get a decent Multipass render with 5 passes, but if the shadows look too grainy, you can increase the number of passes.
AO (Ambiance Occlusion) only works if there is "open sky" above the model. You can't use a sky dome or put the model in an enclosed space when using AO.
As far as your modeling questions, could you please describe more clearly what you are trying to do? Maybe post a screenshot of your model in Shaded/Wireframe view so we can see what your splines are doing?