A:AnswerI am not sure about Nvidia Shield, but this remote cannot control an Amazon Firestick. This is an IR-based universal remote, and Firestick remotes use Bluetooth. You would need a Logitch remote that uses the Logitech Hub.
A:AnswerI believe that the TV button is for a specific brand, so unless all your TVs are the same brand and have the same code I don't think you can do that.
A:AnswerIt can control Vizio tv cec settings plus menu and input like the Vizio remote but I doubt Roku will work if it's the model that uses Bluetooth to connect as this remote doesn't have it. This doesn't work with fire tv. Not with my Xbox despite saying it does.
A:AnswerNot this one. No aux. Get a Roku remote with aux input. This has no Bluetooth. If using wireless headphones, you can buy am adapter to plug into the tv I think that is easier