A:AnswerIf the mount you're using is a standard thumbscrew connection that uses the mounting fingers on the GoPro, then yes, the HERO8 Black should work. All of the GoPro cameras over the past several years use the same connection system.
A:AnswerGoPro cameras use a microSD card. Look for one with at least Class 10 or UHS-1 rating. SD cards made by Sandisk, Lexar, or Samsung have had great results in GoPro cameras.
A:AnswerYou can see the shot before you start recording, but once the recording starts, it will not display a live feed to your phone. You would be able to view clips after they are recorded though.
A:AnswerYes, the HERO8 Black can auto upload to the cloud when used with a GoPro Subscription account. Once the connection to your home wifi is set up the first time, auto upload can be triggered simply by plugging the camera into a power supply.