In campaigns, warbands at sites you rule add to your attacking force. You cannot travel from a site you rule if any warbands are on your board.
A: Yes you can. This gets around the restriction in the relevant minor action (6.5).
A: Nope, as with the other vows, you gotta do it.
A: No. You can choose where to remove them from, but you cannot freely redistribute.
A: Nope! For example, banishing your pawn would only burn half your favor.
A: Add the bandit warbands to your attacking force. You could not kill or sacrifice the bandit warbands, only your physical warbands. Expect your Bandit Crown to get stolen soon!
A: No. During this campaign you are not an Imperial player, so you do not rule sites that have purple warbands on them.