I'll check it out! Thanks!!PreChangelog for 4.12.19 here -> http://en.miui.com/thread-70578-1-1.html
No words about the static background ... lets hope they dropped thad idea !
Sorry I cant give you any viber support. If you dont get any notifications from any App you should check it in Settings -> Notifications .. and set correct permissions.
Here you can find info about RILJ wakelocks http://forum.xda-developers.com/showthread.php?t=2355140