Is there a way to easily tilt the top of my structure? I will need to place a few of these together so that it the roof would be sloping but cannot figure out how to tilt it. structure.3dm (6.2 MB) 
Rotate or Rotate3D commands.
You may need to Explode the structure or Sub-object select to rotate only parts of the structure. https://docs.mcneel.com/rhino/7/help/en-us/index.htm#popup_actions/select_objects.htm?Highlight=sub-object
Shear` is another possibility.
CageEdit can be used to deform part of the structure though it may take some experimenting to create a suitable cage/control object.
I did try 3d rotate and unfortunately it just disconnected everything and messed it up. I haven’t tried shear yet though