QIf I bury a Paper Shikigami to pay for the cost of this follower's activated ability to destroy an enemy Servant of Silence, will Paper Shikigami's Last Words ability trigger the Servant of Silence's ability?

ANo. By the time you resolve Paper Shikigami's "Discard a card," the Servant of Silence is already destroyed and no longer on the field, so its ability will not trigger.

QCan I activate this follower's ability and bury a Shikigami follower even if there are no selectable enemy followers on the field?

ANo. If you can't select an enemy follower on the field, you can't activate this follower's ability.

QIf there are 2 copies of this follower on my field, can I activate each copy's ability in the same turn?

AYes, you can.

QIf I activate this follower's ability and then evolve it, can I activate the evolved form's ability in the same turn?

ANo, you can't.