Okay, so here's the scoop.

I was trying to make a single bathtub family with all of the related elevation information...i.e. the shower rod, the shower head and knob, etc.

Here's what I figured out:

1)  The only way to keep nested geometry from showing up in a view that the actual hosted family is being cut, is to make it shared.  For example, even though my shower rod was above my cut plane, it would still show up in plan since the rest of the geometry was showing, until I changed the family to be "shared."

2)  When I did this, however, it woudn't allow me to drive the shower rod length if the from within the host family if it was a type parameter.  So, I was able to make it an instance parameter and do it no problem.

3)  Symbolic linework in the host family is tricky.  I would suggest using the 3D geometry to represent what you want as much as possible.  For example, if you sketch over your spicket and knob, it will now show up in both views parallel to the view you sketched it, which in the case of doing bathroom elevations, is not what we want, obviously.  I'll write more on this in a separate entry later.

4)  Making the nested families shared also has the benefits of being able to schedule them, as well as turn their respective object category on/off separate from the host family.  I like this a lot!

If you are interested in checking out how I set these families up, post a reply to this and I will post them for you.