Hi @anon27868450!
That’s a very good suggestion. In fact, in one of the posts, I had requested for suggestion on shortcuts for setting handle types (Flexi Edit Bezier Available for Download - #3). I think this is the best possible option for them.
Yes, there would be support for primitives in one of the upcoming versions. But since there’s already a workaround available (add-scale-move the standard Bezier circle or draw polygons with straight lines [with snapping] using Flexi Draw) maybe this could be pushed back a little for now.
I too share your dream 
Right now I am working on implementing uniform snapping for both Draw and Edit tools. And also, I guess, there should be more ways of bringing curves and meshes together (curve surfaces). There is already a lot of exciting work done in this area, which I thought I should understand first and experiment a bit with some new ideas if possible.
Please do continue to share your valuable thoughts and inputs!