How about 1-Click woodworking joints. And not only for wood.

A vortex/twist/swirl function would also be nice but I know this is hard to do with nurbs.
Very useful for tire treads.

And one more: Boolean difference with the option to keep the cutting object.

Instancing?

Well and of course dimensions and a coordinate system ;o) But that's too obvious.

A "Back" viewport if that makes sense.