Assuming you app is called "mainWindow" (because I copy/pasted some of my own stuff here and couldn't be bothered to change it )
For the Icon and App title I used this in the acMain part of the code: ac.setIconPosition(mainWindow,-10000,-10000)
ac.setTitlePosition(mainWindow,-10000,-10000)
Basically hide them away.
To make the background and borders of the app invisible (both at start and after clicking/draggin it) I used this both in the acMain and acUpdate part: ac.drawBorder(mainWindow,0)
ac.setBackgroundOpacity(mainWindow,0)