Inheritance feature layer rules

There are multiple levels of items at work here and what "level" the thing you are adding to a layer lives on comes into play.

For a datum plane, there's the plane itself with lives inside the datum plane feature.  A sketch feature contains multiple sketch entities.  The inheritance feature contains dozens of individual entities.

Once you hide an upper level item, nothing inside it can be made visible.  The hidden status of the upper level overrides any settings on the lower level items.  So, if you hide a sketch feature you cannot make any individual sketch entities. Because of this all my rules put entire features on layers rather than individual entities.  (Quilts are an odd case, they are neither parent or child in this scenario. I don't put them on layers, only the surface features themselves.)

With an inheritance, in the source part you may have put the features on layers but once they are inherited into another part they become entities of the inheritance.  That makes it difficult to control them, as you've found.

A couple of things that are helpful. 

1. Put features only on layers, not entities.
2. Use Isolate to show items instead of hide.  If a feature is on two layers, one hidden and one shown, it'll be hidden.  If one's hidden and one's isolated, it'll be visible.  Hide beats unhide, isolate beats hide.  (There is a new status in Creo 4 that I'm not familiar with.  I'm not sure how that affects things.

The situation you are dealing with is still challenging and I've spend a lot of time (too much time, frankly) thinking about layers.

Sorry I don't have better news.