There is one way to do it(tabbed window).. I
hinted earlier.. But I'm not even gonna try modding it for the default UI
Also it has it's problems:
You'd have to set the tabs where you want them each time you log in..
You'd still need to minimze windows manually into tabs..
I will explain in more detail..
Using the scripts I use to minimze and restore the chat window in tablets you can technically make a fake tab window..
You make it so that it minimizes into a window that looks like a Tab..
And change the restore button to take up whole window..
I have it set up so windows memorize where they were when they minimized and restored and will restore locations..
You would still need to minimze windows manually.. but could probably set them up to minimize when you press escape.. If you added a button that toggeled the IsCancelButton property of the MinimizeButton between true and false.. only windows you wanted to minimize on escape would..