I don't know how far this would take you either, but some kind of parallel storylines can be created. Instead of continuing chronologically with the original storyline, you can make mods or campaigns that parallel events already done in the game or something like that.
How many mods have been done with the player playing as a shivan? Or even have a totally new story that ties together some event in FS or FS2 that was never officially explained. For example (although it's not very accurate because i can't think of any specifics) what about a campaign or mod or something from an actual even in FS2? Since your character in FS2 wasn't everywhere, you can expand on other missions mentioned in your breifings, but you weren't a part of the action yourself. So then the campaign can put the player in that new position in the same storyline and elaborate on some more details/conjecture about the whole FS universe.
I realize that can be redundant, but with good modders like yourselves and careful planning, it could be pulled off without getting boring or repetative.
All the more reason to have a place like this where people can plan out things and make them fit if they so desire.
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BC01