I've been leery of Distraction Free writing since I first heard about it at Raleigh WordCamp 2011.
But I just realized that it is possible to get the full screen edit with a reasonable complement of editing buttons at the top. Simply click Alt-Shift-G (and do it again to go back). [That's actually been in the help for more than a year.]
Now there is a bug somewhere. If you hover over the "full screen" button (between the spell check and the kitchen sink buttons at the right of the top line of buttons), the tool-tip says "Toggle full screen mode (Alt-Shift-G)". But if you click Alt-Shift-G, you get the edit window with formatting buttons. If you click the button itself, you get the Distraction Free/zen mode editing screen.
I think this could all be solved by
o adding another button that would do what "Alt-Shift-G" does,
o correcting the tool-tip on the current full screen mode,
o implementing that keyboard shortcut for full screen mode
Or am I missing something? But please do not remove the ALT-Shift-G functionality!