I am running the student version of Creo 2.0.
How do you extend the edges of the surfaces and what would that do?
I am not familiar with this function 
The same goes for channels..
Regarding contours I "just" need the sketched curves seen on the mask in my previous curve to either offset out from the model or down into the model. The deepest offset into the model would be 4mm i think. The biggest offset out would be 2mm.
I tried remaking the Mask's surface by merging each of the small surface parts, but that only helped a few places (typically the flat areas without too many curves).