1-4 of 4 Answers
Yes I use one all the time for cycling. I have a 6500 mAh USB battery pack and can run the Session for about 10 hours off of it at 1080p and 60fps...
Only to charge but it can not be used while charging.
Yes, you can connect the camera to a portable power pack via USB in order to extend battery life while it is recording for long periods of time.
Yes. As long as it uses a USB-C connector.