In regards to the part the vague noun sections, I think a few more examples would help make clear the many ways can be used. "You left your shit in my car last night." - Used to replace a word similar to "thing" or "stuff", or used to implicitly refer to an illegal thing or drug. Another example:"This shit is awesome." or "This shit's so boring." - Used to show emphasis, can be used with both positive and negative connotations.