If desktop real estate is valuable to you there is a simple way to get rid of the windows decorations while trying to maximize every window using maximus
sudo apt-get install maximus
in case this program fails is doing its job you can always use compiz to achieve the same goal as JakeTolbert clearly explains
sudo apt-get install ccsm
and in Windows Decorations plugin set instead of any
In order to close the windows you could consider adding to the GNOME taskbar the Canonical window-picker-applet (after installing it rightclick on the panel and add the applet plugin).
sudo apt-get install window-picker-applet
you can also use the key combinations ALT+SPACE+C and ALT+F4 to close windows.