How do you import toon cel shading from cinema 4d to be rendered exactly as it was in c4d?
Unfortunately there is no way to do that. Only basic colors and texture maps will transfer, the Sketch and Toon shaders in C4D are fairly specialized, and I don't know of any way to get them to export properly. You might look into the possibility of baking the S&T shader in Cinema to a texture map and export that, but again, that would be just a guess on my part.
The toon shaders in Keyshot need to be setup from a preset, then you can tweak from there. There might be more developments in KS 8 on the toon shaders. Maybe post an image of what you are trying to accomplish and some of the people that have been working the toon shaders might jump in.
Thanks.