Is it possible to make:
YELLOW edges square (i.e. Straight like the edges beneath them)
Green edges square so that I could create a more hard square-ish shape from them (like a square headlamp)
FYI - the Pink is for a different post to follow…
Excited by the SubD in Rhino 7 
yes, mostly: by deleting all the edges running down. imo you don’t really need those edges to define the shape. For Subd key is to work as much as possible in quads, and to take care of right ‘flow’
to refine / sharpen without leaving a quads-based design you will need to have some points that share more than 4 edges. Here is an example:
subd-sample.3dm (131.4 KB)
you can crease or bevel the yellow edge, and you’d need to add some edges to make a square face for the green edges.
