Does Boarding Action work as an attack or movement order? IOW, can you order Board Action and attack units in the Catacombs of the Vengeful Spirit?
Is it a move order that then allows you to target the Catacombs with an attack after the Refresh?
Are there any orders that allow you to attack the current area? More importantly, why would you want to attack Catacombs? Horus is more than likely in the Command Center, so after Boarding Action, play an attack order from hand and attack the CC. If Horus has been moved to the Catacombs, just stay there, there's going to be a coexistance battle.
Activation-Once an area is activated, units there can longer receive orders until a Refresh phase, correct?
For examples, units Assemble in an area, then they would have wait until the Refresh before they could be ordered to attack?
Only if you played Assemble from hand, if from strat map, destination area isn't activated. To combine with your first question, Assemble off strat map (Imperial Palace region) -> Boarding Action from strat map -> Assault/Onslaught from hand = Imperial victory.