Total Full Screen for Android 5.0.2_r1
How to remove statusbar and navigation bar from SystemUI.apk (android 5.0.2_r1)
To navigate the tablet, you need to borrow hardware buttons. For example re-map POWER button in /system/usr/keylayuot/Generic.kl to BACK button. So when you do a short press, in will act as you pressed BACK button instead of turn screen on/off. You can also utilize vol-up/down button for BACK or MENU.