Couple of questions:
I take that you can take actions without presence at any given planet as long as there's a battle going on.
A. Can you use/trigger battle abilities on other units from other planets? Taken that it's not in the current resolving battle?
If yes, does this apply to units that went home (HQ) from the previous battle.
B. Can you target other units not at the current battlefield? (of course unless it's specified on the card that the ability must be used in the planet.)
C. Can the warlord use events like nullify even if he's at the HQ?