Post-Capella-era campaign ideas
These are concept campaigns for the Reconstruction era: Add yours at the bottom of the list.
Flying Shotgun with the Shivan Defence Force
I haven't seen any campaign you play sa the Shivans on, and it would also shed light on the motives of the Shivans. It might be a big mod because I'm sure the Shivans have all sorts of weapons, ships, etc that we haven't seen, and a modder would need to seriously flesh out the Shvan arsenal (would you take a shivan loadout screen seriously if it had Shivan Mega Laser on it?).
Reconquest of Earth
Description: Exploration parties have found a new way to Sol (through the Shivan nebula?). Unfortunately, the Terrans there are not willing to become part of the GTVA (reason to be established in campaign). The GTVA and Terranovan Confederation (or whatever else you want to call it) duke it out (possible multiplayer head-to-head campaign). Possibly, if the route is through part of the Shivan Nebula, have a three-power war between the GTVA, TNC, and Shivans.
Modding: Do not make this campaign unless you like modding or you don't care about plot holes. To avoid plot holes, you need to either plagarise a lot of FS1 craft & weapons or do a lot of modding. Neccessary: Make an Orion with Shivan beam weapons (they got them by REing the Lucifer debris) (Terran beam weapons weren't invented until after Sol was cut off, so GTBWs on a TNC Orion would be a plot hole); if it gives them a serious advantage, make weaker versions, because leaving the Confederation's Orions without beams would give the GTVA a major advantage. Either Resurrect the Athena and Valkyrie at a minimum or make new fighters solely for Confederation Pilots; make the selection good enough for until the Confeds RE GTVA fighters. Do the same for a decent selection of guns and missiles (beam weapons can be copied from the Shivans). Optional: Make a new race called the Terranovans (Latin, literal: New Earth; figurative: New Chance). Give the Terranovans some sort of signature technology, eg a fighter with AWACS technology or support-ship capability, or give them Shivan technology. Balancing: If you have a three-power war in the Shivan Nebula and the Shivans overpower the Confeds easily on easy or very easy, either ask yourself whether you need the Shivans to have as much firepower, or give the Confederation a shield-penetrator; if this doesn't help, rethink the mission(s) in question; if the GTVA is almost as badly outmatched, have them RE the penetrator.