I'm working on a map concept right now. It's an NS classic map, aboard (suprise) a ship. I don't have much of a backstory yet, but I'll make one (in english class or something

). So far, for an ideas, I've decided to have the "classic" rooms, such as an armory, cargo bay, engineering section and galley, but I'm adding a few that aren't on most NS ship-based maps. I'm including a medical bay, bridge (in an important function, rather than decorative) and hangar (complete with dropships and fighters). The map will only cover a few decks of the ship (no stacked rooms obviously). There'll be a hive in the amory, bridge and engineering. MS will be in the hangar. Yes, the hangar is nice and open, but there can be some strategically crashed fighters or dropships to create a chokepoint or two if necessary. The aliens have taken over the key systems on the ship, including weaponry, so the ship attacked the TSA dropship carring the fronteirsman, which crashed in the hangar, smashing up some other craft into very convenient positions. When I get time (on the weekend), I hope to whip up a little concept diagram.
As for questions... how dark is too dark. Since the power systems of the ship has been infested, I was thinking of having a marine chokepoint in the form of a nearly pitch-black room. Not a big one, and only one. Also, I want the map to be darkish in general, a bit brighter than co_plague tho, because otherwise its unbalanced for marines. As for the dark chokepoint, I'd like to think it adds atmosphere when a squad of marines walks into a pitch black room with their flashlights scanning it.
This is my first NS map, so any criticism is EXTREMELY welcome.