it will be helpful to constrain the move axis either by holding Alt key or pressing C key as we do in knife. this feature is available in sketchup if we move the object and hold shift key it locks the axis.
Ortho mode is really powerful for architects and engineering, if you could design such thing it will greatly help to switch architect to blender. I know it is possible because knife tool already use it in screen space.
Constraint to axis is possible the same way than regular blender transform operator, using xyz keys.
Pressing C currently allow to setup a custom constraint axis.