Honestly, the Crusader's amazingly well-balanced, though with a bad habit of ammo explosions due to it only having 10 Heat Sinks (alleviated by the 4BR using DHS). About the only real modification you can get away with that would take only a week or two of time would be to yank out the MGs and ammo, and slap in 2 more medium lasers into holes made by removing the MGs.