I've a question
Why root the chromecast ?
If its ever been updated or it was purchased recently it not rootable through a y cable. You are gonna have to rip it apart and JTAG it. The only real benefit I can see of rooting it these days is region blocked content. But there are ways to do that through a router.
So back to the question of "why". Are there any firmware improvements on missing features available like?
- remembering more than one WLAN password
- the ability to mirror and stream content from a device via direct connection without the need of a local WLAN
- support for more file types