I found the place to request features;
It's under 'Bugs' - oookay..?..
http://calibre-ebook.com/bugs
Anyway, it doesn't matter.
The reason it doesn't matter is because I'm a newbie and haven't invested the proper amount of time in the program.
The doc paths pop up when hovering over the format (EPUB, PDF, etc).
Fantastic tool - thank you all so much,
Cheers...