QCan I select and destroy this follower with Dark Offering?

ANo. You can select it, but it will not be destroyed.

QIf I select this follower with Dark Offering's ability, can I still play the rest of the ability?

AYes. Heavenly Aegis will not be destroyed, but you still give your leader 3 defense and draw a card.

QCan this card be destroyed by spell abilities?

ANo, it can't.

QWould this follower be banished by Hare of Illusion's "Banish each follower on the field" activated ability?

AYes, it would.

QDo I have to pay 2 play points and discard 3 cards to evolve this follower?

ANo. You can choose to either pay 2 play points or discard 3 cards to evolve.