What the hell, it looks like there's an inventory item floating outside the game area at the top of the map
This is really cool, Shane, the only weakness of your system I can think of is that it may not include containers with inventory items in them - does it? If not, one way to fix that would be to write a function that destroys all containers that you can use before you highlight inventory items.
I don't really want to remove every part of the map that has nothing. The area in the lower right that you pointed out as empty serves as eye-candy of nothing else, and adds a bit to the plausibility of the level structure as a city wherein people live. It might be an idea to add something there though, maybe a hidden item or a wandering civilian.
All in all, I think we have a pretty good interest density. Please don't make a similar map of the Corporate sector, I suspect that would be depressing, since Corporate is a hub to a far greater degree than Downtown is.
Ooh I just noticed the girl who's supposed to comment on the lack of public transportation is missing from the bus stop. I should re-add her!