Q: Will a stun status card prevent Norman Osborn’s attack activation?

A: Yes. Because status cards take priority over all other abilities, a stun status card will prevent Norman Osborn’s activation. -(Official FAQ)

Q: While Green Goblin is attacking, if the last madness counter is removed from the State of Madness environment through a “Boost” ability, what happens?

A: Green Goblin immediate flips to Norman Osborn form. Boost icons from the boost card are then added to Norman Osborn’s ATK value of *, which is treated as a value of 0. Norman Osborn then deals damage from the attack equal to his modified ATK value (base of 0 ATK, plus the number of boost icons on the boost card). In this specific situation, Norman Osborn’s “Forced Interrupt” does not trigger, as the attack is already past the point of “When Norman Osborn would attack...” by the time he changes to his Norman Osborn form. -(Official FAQ)