A:AnswerIt does not have battery backup. However when the power is restored it automatically reconnects to your wifi and displays the correct time. Yes there are multiple choices for display features.
A:AnswerYes you can configure alarms from verbal commands or by using the touch display. In addition to a Wi-Fi connection you'll also need the Google home app to set up the device initially.
A:AnswerThere's an option to have the display stay the same brightness throughout the day or have auto brightness where it will dim to really low brightness level when it's dark in the room. If you tap the box it lights up for about a half a minute.
A:AnswerThis clock has a display, but cannot display pictures or videos. For $15 more the Google Nest Hub has all of the same functionality, but also much more - it should be able to show your Arlo cams, assuming they're compatible with Google Home.