untested but have you tried adding 'Rotation' to the proplist? so change :
'(Insertionpoint XEffectiveScaleFactor YEffectiveScaleFactor ZEffectiveScaleFactor)
to
'(Insertionpoint XEffectiveScaleFactor YEffectiveScaleFactor ZEffectiveScaleFactor Rotation)
If you have a finite number of sheet sizes/layouts, you can add them to your template. It's a lot easier to delete a layout than to create a new one.
Ideally, you should only have to define a page setup once. When you copy a layout, the page setup goes along with it.
Unlock your workspace. You can't manipulate any window elements with them locked. You can press the drop down arrow and pick which elements to unlock, or simply lock them back up once you have fixed your problem.