I'm going to piggy-back this aptly-named thread with my own question:
Is there any way for Machines to move a Structure through their own HQ, on its way to a(nother) region they control?
The wording of "Moving City" seems to indicate a "from 1 to 1" sort of move, but I'm no master of the game yet.
No structures in HQ. You can only violate rules explicitly stated by card. Keep it simple.