I'd like an option in 3D sketch mode to constrain lines to be "Along X,Y or Z" which would basically constrain the line to be parallel to the referenced axis.

Also, it would be nice to be able to constrain points, lines, or other geometry to be "on a plane" Which would avoid the step of having to make a 2D sketch on a plane (if the plane is at a variable angle) to control 3D sketch adaptivity.