QI play this follower's Fanfare ability while there are at least 10 cards in my banished zone. If I then play a Runecraft follower, can I choose not to evolve it even if I have the evolved version of that follower in my evolve deck?

AYes, you can.

QI play this follower's Fanfare ability while there are at least 10 cards in my banished zone. If I then play Imperator of Magic, whose Fanfare ability searches for and summons a Golem follower, can I choose whether to evolve the Imperator of Magic or Golem follower?

ANo. Imperator of Magic is put onto your field before the Golem follower, so you must choose Imperator of Magic. However, if 1 or more Runecraft followers are put onto your field at the same time, you would be able to choose which one to evolve.

QIf this follower is put into the banished zone, does its automatic ability trigger?

AYes, it does.

QI have this follower on my field. If I put Leeds, Pining Witch into my banished zone as part of the cost of its activated ability, does this follower's automatic ability trigger?

AYes, it does.

QDuring my turn, if a token follower is put from my field into my banished zone, does this follower's automatic ability trigger?

AYes, it does. The token is put into the banished zone, then it is immediately removed from the game.

QDuring my turn, if 2 cards are put into my banished zone at the same time, how many times does this follower's automatic ability trigger?

AIt triggers 2 times.

QIf I evolve another follower with this follower's ability, do I still have to pay its evolve cost?

ANo, you don't.