yeah, its called a skeleton part. skeletons in my opinion are more limiting than an actual part used as a skeleton.
skel parts are something ptc stole from an intelligent user like yourself using a part exactly the way you are using it. to transer design intent from the top, down. top down design is a very robust design philosophy. layouts fit into the (top) picture but they need to be a bit more powerful i think.
you sound like a innovative person with pro but this technique has been robbed already. thanks for the reply