If there is not the slightest chance of anyone being affected by you moving off, including oncoming traffic and pedestrians, then there is no need for signalling. However, we recommend always signaling before moving away.
If you are ready to move off and you see a vehicle approaching from the rear to pass you, do not indicate off if you intend on waiting for them to pass. Wait until the vehicle has passed.
The stopping distance will depend on your attention, the road surface, the weather conditions and your vehicle.