New ship Ideas: (I've refrained from looking at playthroughs past chapter 2 to not spoil the game, so I wouldn't know if this is in the game already), but a pitch black or dead ship in complete darkness except what ur flashlights reveal could be fun. A thousand malevolent eyes in the darkness.
Existing maps could hav a 'night mode' as it were.
Maybe things could be affected by the cold such as plasma batteries are cut to half, slower to recharge, guns jam more often etc. Blip sensor could break down.
Also, a Dark Eldar ship could have heavy internal security systems, traps, laser beam security, force fields etc. Then again this might not work for the nids either so could be impractical.