Beating FreeSpace, like any game, is all about understanding simple tricks and procedures, not having some dazzling reaction speed, coordination, insight, or whatever. Stay near friendly capital ships, avoid flak, lure enemy fighters toward your wingmen, and you'll beat every mission, it's as simple as that. Even "super-hard" missions like Bearbaiting are just a matter of playing through it 30 times and making an effort to correct your mistakes until you get it perfect. Multiplayer is a whole different ballgame because you actually have to think and use creativity.
And although Derelict was quite easy, there are a handful of real challeneger missions. Having Invincible Mackie by your side all the time makes the campaign three times easier, though.