Hi nycL45, you wrote:

> 1) I drew a spline using polyline, line and arc, joined them and extruded but could
> not "skin" the major faces despite checking Caps, trying Planar and rebooting.

This would usually mean that those different curves were not quite touching each other end-to-end. If you could post a .3dm model file with those curves in it, I could take a look and see if that was the problem or if it was a bug.

- Michael