Do commanders take up agent spots (i.e. count towards the 5 or 7 card max)?
From their appearance, I would guess not, but on the website they're called "commander agents". If they are agents, can they be killed, stolen, or extracted?
Commanders are never played or kept in hand. They sit out on the table in front of you as a reminder of the special ability you have. They are always active for that player only. They can not be targeted by any ability currently in the game.