Pardon me if this has been answered before.
Are regions with a Trog War Party or Nest token, but no Trogs, considered to be "unoccupied"?
Another question, then, is which structures can be built in an area the player doesn't control?
Occupied: Has minis/Units
Unoccupied: Does not have minis/Units
Tokens have nothing to do with occupation.
2. None. You can only build structures in Regions you control, not your HQ, and not a battle region. This is a global rule.