Gave it a shot: It threw some errors about missing models, but it wasn't TOO hard to zip around (nearly parallel) to the main asteroid belt at high warp, cut in, and beam out most passengers without anyone getting to fire a single shot. The rest was just taunting and kiting the baddies to their doom.
The harder part, of course, was getting everyone OUT of the KM before it went into the singularity itself.
I've been thinking about this one for a while: It's better suited for GM control to properly throw everything possible at the player. Nebulae certainly help manage the speed concerns, but you'd be better served by warp-capable elites, and keeping the nebulae around the main "arena."
Basically, if you want a no-win scenario, it should be tweaked such that there's no way to get to the Kobayashi Maru AND beam everybody out before the first fleet shows up and opens fire. Beyond that, the remaining fleets would be ideally programmed to appear once the players cross the Neutral Zone barrier, preferably between the player and the station. At that point, they shouldn't exit Neutral territory either, but should merely close in on the player, leaving few avenues of escape.
Don't get me wrong, this is a really neat starting point, but capturing the spirit of the Kobayashi Maru simulation is HARD. Keep at it! I'd love to throw this at a fresh crew of five, no assigned captain, to see who rises to the occasion, and as such, should lead the crew from then on.