A:AnswerYou cannot control devices which are not registered in your home on the google home app or devices which do not have said features. However the Google TV Essentially converts your non smart tv into a Smart TV with Google assistant and can be controlled by a Google Smart speaker or Nest hub devices.
A:AnswerYes. You can set up Nest Mini to announce visitors with your Nest Doorbell (Battery or Wired). Read more about how you can set this up here: https://support.google.com/googlenest/answer/7672451