Most flyaways are compass related and like most drones you need to avoid places of magnetic interference. Doing the compass calibration in a large open area away from power lines, cell towers, reinforced concrete and such will usually mitigate that problem.
The only bricking that I have heard of is when a person formats the Breeze’s internal memory using something other than the Breeze Cam app. If you don’t use a PC, tablet, or phone running Windows, OSX, Linux, etc. to format the memory and only use the Breeze Cam app to do that you should be fine.
The geofence on the Breeze is 80 meters in height and 100 meters in distance which is about right to remain visual line of sight. At those distances it can be hard to regain sight of it if you look away too long.