QWhen banishing cards in my deck for this follower's Last Words ability, do I put them faceup or facedown in my banished zone?

APut them faceup.

QIf my hand is empty, can I still play this follower's Last Words ability?

AYes. In that case, you would simply not discard a card.

QIf I choose not to pay the cost of this follower's Last Words ability, do I still discard a card?

ANo, you don't.

QIf this follower's been given Ward by something like Death's Breath, does it lose Ward when it's put back onto the field with its Last Words ability?

AYes, it does.