Panic (Long War)
The two main sources of panic in the Long War are Terror Missions, where an excellent mission only minimizes the Panic raise that will occur, and public UFO sightings in uncovered countries.
For Satellite Coverage, since Uplink and Nexus capacity has been halved, you'll need more to fully cover all Council nations. The ideal Satellite facility configuration is now a 2x3 block, with 3 Uplinks and 3 Nexi-- which you might not need in full, sicne you're near-guaranteed to have one country withdrawl in the first month (at least not until late-game, when you liberate it). Still, coverage as soon as possible is ideal, so at least you can manage any smaller craft that come into covered airspace and temper down panic. But try to keep some extra satellites in reserve, for when the inevitable Battleship comes for your satellites.