Simple solution, make the passive spell an active spell with a 30 second cooldown. If you want your pet to fight for you, it's your job to maintain it's survivability, adding a skill to manage the pet makes sense imo and removes the trivialization of using pets on mobs with harsh aoe's.
No. This would kill your pet in any pve/pvp situation.
Having to micromanage my pet when trying to solo things is a pain enough. Just revert it and leave it the way it was.