Blend Surface / Trim

I am building  a model on SolidThinking Evolve 2015. I am attempting to blend surfaces but I am struggling.

When the console prompts the selection of “edges near start on surface” there is only one possible edge to select however, I wish to blend the surface with multiple surfaces.  Is it possible to create more edges on a surface?

I have blended some of my model. Next I trimmed a section out of a surface. Once the surface that has been trimmed evolve seems to create another surface called 'trim' - is it possible to trim a surface but not create a new one? Or combine them? As now all my blended surfaces are corrupt. 

Any help would be much appreciated!

Thanks