Unable to root but food for thought.
Okay, I messed up and mis-spelled eureka-image while rooting and didn't pay attention and let the device update after I rebooted it after a couple hours of being gone then I was stuck in google locked down build.
Well this got me thinking if we can't root can we make "Chromecast" believe we are using Google Movies when in fact it is a 3rd party app?
Wouldn't we just need to find the string that communicates that the 3rd party app is Google Movies, or Pandora or any of the Official Apps?
I could be wrong but I think there is away to make it work but it'll have to be built in the 3rd party's app.