About 10% of SFB is in SFC. There's lots more that could be added. More races with all new ships, systems and weapons, just for starters. If I were making it, which I realize I'm not, I'd add boarding party and ground combat. There could be a whole strategic level added. Any of these things would make it a whole new game with lots of reasons for new players, as well as disenchanted old players, to join in.
I would agree. In my belief SFC4 should be an evolution not revolution. The game already is the best, adding to the abilities is what is needed, not make a whole new game (if it was a totally new game, then it should have a whole new name not just a series number).
SFB has so much that can add to the game, but you have to be carefull on how it is added as it would be easy to add so much that it becomes unplayable because you have to much to control. Writing better AI controllers for systems would be nice.
Going along with Frey and tracking crew. Maybe link different scripting styles to each crew member (station) thus you can customize how your ship acts in combat. That way you can't totally know what the other ships AI will do so it is harder to plan on how to fight it. (smarter boarding party actions, no beaming over when the enemy drops a facing shield so he can alpha strike you when your AI drops your shield). Little things like that.
Maybe add the ability to have local scripts in (pick your scripting language), so you can tweak your own ships way of fighting. Making sure the scripts only direct action and doesn't dictate it would help keep people from cheating with them.