Coming into this project it seems to me that there are certain logical categories of information that metadata is grouped in.  Initially I had seven categories (* below) but there are three others (4/28/15) I can think of and I decided to consolidate two in Qualities:

Although this may look like a lot of information, in most (if not all) cases are going to use only a small submit of the fields, and even fewer will be 'required'.  It is important here to try and capture all the information users might need/want.