I was able to create a chat window that Has Minimize and Restore Buttons..
Also added a button to toggle the input area on and off..
None of it saves when you log out though.. When you log in all chat windows will look normal again.. If you had a minimized window it will be minimum size..
I think it's a good idea NOT to remove the input bar or minimize your mainchat window (IE 1st chat window).. You will no longer be able to bring up the chat input with enter, or '/' , etc..
When the input bar is missin; to resize the window from the bottom you have to grab where the bottom frame would be on the input bar..
Top 2 buttons on upper left of title bar