A:AnswerNo. Nest Hub can only be connected to the internet wirelessly. There's no ethernet port for a wired connection. Also, the power input range for Nest Hub is 100V - 240V, 50/60 Hz. Any input level within this range should work. Take a look at this link to see Google Nest and Home device specifications: https://support.google.com/googlenest/answer/7072284
A:AnswerYou can stream a compatible security camera on your Nest Hub. You can check this link to learn about streaming your security camera using your Google Nest display: https://support.google.com/googlenest/answer/9137164
A:AnswerYes. Once the Nest Hello Doorbell and Nest Cameras have been successfully linked with the Nest Hub 2nd Gen, you can use voice commands to stream the Nest Camera/Nest Hello to the Nest Hub 2nd Gen. You can use the command, "Hey Google, stream <name of Nest Hello doorbell/camera>", to stream the camera feed to the Nest Hub 2nd Gen.
A:AnswerIf you're referring to the Nest Hub's theme, you can check this link for the instruction: https://support.google.com/googlenest/answer/10243683
A:AnswerYes. Any google mini or smart speaker can be used. They all work independent, but you can play music through them all using the play all function, or play each independently, I have 9 minis / smart speakers throughout my house and often play music throughput the house.