Humm. I leveled my Druid as moonkin and I dont recall having any issues in Deepholme. She is still there because I just log in a bit and blast down the troggs to the East/NorthEast for free xp as they fight the stone dwarfs.

She was pretty squishy at first when I did Hyjal and I think I did die a couple of times in deepholme when I got overrun. Seems like maybe having to pre-hot, fight, then hot again while going to the next mob fixed most of that till you hit the 80k hp range.