If you want to be a melee powerhouse, one level of bloodrager, vital strike, and furious finish along with behemoth hippo bite damage with strongjaw is just frightening. You don't really need power attack at that point.
To be a good caster you just need natural spell and augment summon. Anything else is gravy when you can be effectively invisible as a small bird.
Archetype/domain/pet to flavor.
I will second the party issues with the blight druid. I actually really like mooncaller.