Earlier quoted context omitted.
Limit the need for Explorer/Finder/etc. altogether. For those cases where it is needed limit top level UI elements to the most commonly used items. Move the rest to either a toolbar or a contextual menu. You know, I just checked Finder and realized that not only does it not have the things showed in this mockup, but that I have never missed them. Strange.
Did you consider that you haven't missed these things because you aren't used to using them?
I can give you the steps, if you'd like.