For moving out of things, many people broadcast either the strafe keys or the arrow keys and use them to move the slaves. You can also try using follow and/or IWT if the situation allows. Take a look at the Movement section in the Second Newbie's Guide.

As far as swapping, you've got multiple specs available. You can set the druid and the shaman up to both have the ability to DPS or Heal as needed. Many people prefer to have their "healers" run as DPS in instances so they can kill things faster rather than having a toon standing around waiting to heal. And since both the druid and shaman can throw out spot healing in their DPS spec, you won't lose much, if anything, running them that way. It also gives you the ability to have 2 different healing styles available to chose from based on the encounter.