Cannot be Normal Summoned or Set. Must be Special Summoned with "Rose Bud" and cannot be Special Summoned by other ways. Each time this card inflicts Battle Damage to your opponent: It gains 200 ATK and loses 200 DEF. Your opponent can only target "Elemental HERO Poison Rose" for attacks.
No, if you controlled two Elemental HERO Poison Rose, your opponent would still be able to attack.
Dyna, Hero Fur Hire can prevent the opponent from declaring an attack because its card text states "...cannot target monsters "Fur Hire" for attacks, except this one." and not "cannot target monsters "Fur Hire" for attack, except "Dyna, Hero Fur Hire".".