Nope, no pie controls or any other soft key apps work apart from Button Savior app so at least now I have control of the phone and can go back/home etc instead of having to restart every time. Even in recovery the back/home keys do not work so it seems to be physical.
Still can't work out why this has happened. I seen loads of posts from searching about the digitiser being faulty but the phone was working fine for almost 2 years now and I never dropped it.
Doesn't matter now, Moto G v2 will be here today. I just don't know what to do with this Nexus 4 now. It works as a phone 100% you just have to use different buttons to navigate