Major1) Absolute altitude should absolutely work. Also in face of bad GPS init. How does the mission planning part work with that, how is alt. stored in waypoints? When is home altitude stored in the UAV?2) Some people have worse datalinks than average - eg. slow or noisy telemetry. GPRS data also easily gets flooded. All data rates should be configurable and uplinks eased off a little.3) Some streams should be sent always even if not in use. For example using RC override and then stopping using it: If the UAV does not received the final RC override message with zero values for all channels, it will not get out of RC override. A solution is to make the message non final, repeating it every now and then.Minor1) I would like to see initial dummy values for eg. battery voltage go away and be replaced by "unknown". Dummy values confuse, you won't know if your sensors and link are working or not.2) Suggestion if the DO_JUMP behavior of APM today (where DO_JUMP requires a waypoint command after it): Modify APM code so DO_JUMP is regarded a navigation command. Make non navigation commands appear in planning as sub commands of navigation commands (indent them). Easier to understand.3) Old style audio with signals/bells/beeps / Morse may be prefered by some. Maybe add slots'n'signals for all audio and different implementation types (speech, beep, ...). Or a generic operator messaging thing.