Never thought that 3G would be considered for connection to the camera. You are correct - it lacks the reliability that we demand from our equipment - for many reasons besides the two you mention. On top of that, could you imagine paying AT&T just to use the interface? Ack!
The 3G is only good as an internet connection when WiFi is not available, or if you want an extra GPS.
Whether RED chooses WiFi or Bluetooth as the interface with the camera, I'm sure that they are going to test it to death and beyond before staking their reputation on it.