Currently all objects placed into a family must share the same behaviors, and there can not be any added that have different behaviors.
What I would like to suggest is the ability to add objects that have additional behaviors, but still share at least one common behavior.
For example, lets say I have a game like Warcraft, where I have characters that do both melee, and long range actions. If they could be grouped together it would be a lot easier to have an event like on click family go to object.