QIf each player reveals an 8-cost follower or amulet, who summons their revealed card?

ASince the costs of all the revealed cards are the same, all players summon the card they revealed.

QIn a 4-player game, if two players reveal an 8-cost follower, one player reveals a 7-cost follower, and the fourth player reveals a 6-cost amulet, who summons their revealed card?

AThe two players who revealed an 8-cost card summon it.

In this case, the costs of the revealed cards in order from highest to lowest are as follows: 8, 8, 7, and 6. The cost of the second card is 8, so the two players that revealed an 8-cost follower summon it.

QWhen resolving this amulet's Fanfare ability, if a player only has spells in their hand, can they still reveal a card?

ANo. Each player can reveal up to 1 non-spell card, so that player would simply do nothing.