For looting, I put it on FFA and only have the other guys loot something when it's necessary for a quest or something. Otherwise I just trade them stuff and have an auto-accept macro. It's actually not that bad, especially with the kill speed of a 5 box team.

Shaman and druid are a great team as casters, epecially into the future when a druid will grant a nature dmg buff and has spell hit and spell crit abilities that help both. Stick with them as pure casters. I wouldn't bother with a melee team of shaman/druid, it would get so confusing.