Arnold I think you've done a great work! I would suggest also the use of specific start parts for the solid pipe part and the assemblies. I explain better the reasoning: when you use the piping module you have the pipeline features inside the model. Those features, in my opinion, are annoying because are the first target of the smart filter selecting system. So I've created a start part and a start assembly that containg rules to create layers for each type of piping features. Those layers are in hidden mode so I see (and I can select) only the "solid" of the pipe.
