I think the levels of distinction are good, but that's because I'm heinously postmodern and if one has to have categories at all, more categories = better because they can be more specific.
However whenever I find myself looking at other people's EFBs I'm almost always after a particular family, and don't necessarily know what level their family is, so I have to do a forum search.
I would suggest the approved EFBs just be listed by family name, but then have various indices grouping them by class, line of work, country, blood status.
Could you not make a sortable table with columns for Family name (including a link to the thread), Location, Class, Line of Work, Anything Else Important, and then people could click on the table headings to sort it per their needs at the time?