Pour la question 3, je viens de trouver ceci sur boardgamegeek, qui indique que quand on est sous sa forme alter-ego, les dégâts ne vont que sur les Alliés (s'il y en a), l'Alter-égo ne subit pas de dégâts comme le texte de la carte n'indique héros et Alliés
"Explosion
When Revealed: If Bomb Scare is in play, assign X damage among heroes and allies where X is the amount of threat on Bomb Scare. If Bomb Scare is not in play, this card gains Surge
-damage cannot go on alter-egos (as the text specifies "heroes"). Which means that if everyone's in alter-ego the damage just goes on allies, and if you have no allies in play, the damage is just gone"