well, a Starcraft --> Freespace conversion would work, but how is a player going to fly in a 2D (Starcraft) environment? In a 2D environment, you're missing one axis, so if you head in the right direction, you won't miss when you fire! It'll be like those old arcade games, or like RAPTOR (if anyone remembers that game, cause it was awesome)...
i mean, it's nice cause they already have the background (the stars, the space) but the whole aiming problem wouldn't work i don't think, and MODding it would be hard --> impossible, cause in all the years i've played Starcraft, i've seen hundreds of campaigns, and thousands of missions, but i've never seen any actual MODs. of course with the experience us in the Freespace community have with MODding, i'm sure it might be possible!