It feels like a thing Sketch-Up should support, I know shop is meant to be basic, but Circles are basic as well, even in architecture. Also, showing shortcuts while hovering over a button would be great because that’s how I prefer to learn them.
Yes, NURBS would be great. I fear it is unlikely to happen as that would require a total rewrite of SketchUp with a new totally different “heart”.
Unfortunately, SketchUp work only with basic lines and faces. Circles and curves are in fact lines with a smoothing effect.
Nurbs is more a mathematical approach that is not compatible with drawing entity behavior from SketchUp.
3D ≠ 3D
SketchUp is a polygon modeler (edges and facettes), for a NURBS surface/solid modeling you need to use a NURBS modeler too.