arcane abilities of new pets: gives shield, increases gold loot and luck

so, questions:
-shield same as cottonkill AA or weaker?
-does heroic oswald arcane ability adds some dmg (same as heroic cottonkill AA)
-how much gold loot and luck it adds?
-does that luck stacks with elixir, lucky amulets/artifacts, another arcane abilities with luck, awakens?
-when can we get %luck %gold loot %speed at our avatars?