If I have a healer character, acolyte I think, and have no one to heal in a turn of combat how do I skip that characters turn and allow the enemy to take their turn? Must be something obvious...

There is a little shield button on the bottom of the screen which causes your character to defend for a turn. You can use this instead of healing, it also gives you the added benefit of only taking half damage until its that characters turn again.

Nice one fella.