1. The aircraft has a unique capability called DO (désignation d'objectif), it's a manual radar track. It means that the pilot can input the position, speed, bearing and altitude of a contact reported by a GCI/AWACS and follow the contact from far away and radar off (hence the 160nm and 320nm range). It works as long as the contact does not change course or speed. It can be useful for bombers for example.
2. The training missions are a a bit old, the module have been updated a lot lately so that might have changed.
3. I only use the range switch to change the range on the radar and I didn't notice a problem going into 160/320nm, I will test it when I have the occasion.