I agree that it is actually a strange step to have to open a file manager so as to be able to "unmount" or "eject" a USB device (albeit a data storage one). I do remember how archaic this was before: As root having to "mount " and "umount" the device and give it user rw permissions ..... guhhh! 
I don't think that a cairo-dock applet is the solution and as @maxinou mentions: 3.0.x had this covered nicely. E16 doesn't really offer nice ways of doing this on the desktop AFAIK so it looks like slowly but surely we are shifting to E17 (or higher) again. 
For now we have E16 on 3.7.x..... let's get that unconventional flagship working as nicely as possible and be a showcase for what is to come.
Like with holidays: The expectency and the planning beforehand is almost as much (or sometimes more) fun as the holiday trip itself.
