Hello!
1) Yes, a Crystal_Material() can be applied to objects and allows you to add ambient occlusion. It can also be applied to layers using a Crystal_MaterialLayer (I am using it in the first platformer example - the brick wall)
2) Yes, you can add reflections using Materials too, and it is also possible to write your own code and submit it to the renderer using crystal_pass_submit()
I hope this helps, thanks ^^