I agree, the tutorials are not really very helpful imho.

I'm trying to figure out how to use SketchyPhysics and I've tried
several "tutorials". I uploaded part of a sample file to the 3D
Warehouse so I could reference it when asking questions. It is called
"sketchy puppet"

First, I notice that many of the hinges in samples have a line through
them. What is its purpose?

Second, I have been trying to recreate the shoulder joints on the
puppet and I cannot figure out how to make them. I used "unhide" and
discovered that the hinges appear to be inside spheres. Would anyone
be able to give me step by step instructions on how the shoulder
joints are put together?