I do think that having some kind of parent-child system that is easy to use would be a good thing. While you can do this with pointers and handles, sometimes i have wanted an easy way to simply "destroy all children entities". So instead i have to make some junky function that loops through all objects or has some linked list or whatever..It would be nice if you could set the parent object at creation, and then that parent object can have a special function like:

remove_child_ents()
hide_child_ents()

or whatever....

and of course the child objects would get a special pointer "parent" ..