I made a sovereign this morning and, after realizing the "tiny - multiple continents" map is the same every time, wanted to change her spellbooks.  I found the right-click to delete sovereign option, but no "edit" option.  This would be nice.  It would also enable one to find out more specifics about the supplied sovereigns and to make changes to other players' sovereigns.

It's not a huge category, but making a sovereign is sort of a mod.  I can see people sharing their favorite ones, and it would be nice to be able to make changes to sovereigns you've downloaded.  If the face/hair/clothing/etc. options are greatly expanded, creating a sovereign could become sort of like making a Mii.  You'd see Woody Allen and Michael Jackson sovereigns, and it would be nice to see how they were made without going into XML and whatnot.