I never used window decorations to maximize / minimize windows, but keyboard and mouse/keyboard shortcuts for all operations.
In the good olde days, you could just disable and tweak the window decorations plugin from Compiz settings manager. In 14.04, this is not possible.
How can one get rid of the top window bar with the close / minimize / maximize buttons?
Fortunately, all Unity decorations are defined by the Unity gtk3 theme (see this document), and one can remove the top decoration with one little change.
However, just to be on the safe side, I do make a backup copy of a whole theme. Here is what I do:
One last thing to do is to modify (as root) the file
/usr/share/themes/Foopance/gtk-3.0/apps/unity.css
:Change the line
-UnityDecoration-extents: 28px 0 0 0;
toThis is all it takes. Now you can select the "Foopance" theme using the Unity Tweak Tool. The window decorations will no longer be shown!