You'd want to be able to rotate around the center of the selected area, if possible. That would give a sharper angle. Translate would be the same thing as moving just the selected area in a planar fashion. For instance, to make the nose longer, you'd select just the bridge (leading edge) of the nose, then apply negative z trans to the selection. You're exactly right about move along normals. That would give you a 3D expand/shrink. Are you thinking it's possible?