All of these cards seem quite overpowered to me, and they are all Hunter cards!
Explosive Trap is basically 2 mana deal damage to all enemy minions. Snake Trap is fine that it creates three 1/1 creatures, but they also count as beasts as stated in the blizz videos, which means they synergize like crazy. Bestial Wrath's Immune bonus is just so strong, it didn't need the +2 atk as well. (As a side question: Is "Immune" simply prevention of all damage? Since the new mage card makes the hero "Immune".) Hunter's Mark should not cost 0.