There was a null pointer exception with the external camera, also the external camera has a different orientation I've just pushed up a new system.img, camera-app and cameraplugin, once you've pulled them down and rebooted you should be able to get the camera working to a better degree. I still find that I occasionally get that permissions dialog but generally after a fresh reboot it goes away. I also never finished working out the video side of things, so that will still break things, generally after you've tried that you'll need to reboot too.