What it says on the tin. A locker room for each containment zone; in the light (starting), it might be a bit haphazard, like people were leaving in a hurry, with a pistol or two on some benches for cosmetics (obviously you could not pick them up,) with useful items including a first aid kit, a radio, and other mundane (yet useful) items; in the Heavy, you would witness a deliciously gory scene in a military-style storage area. Weapon racks! Because assault rifles are fun; again, they would just be cosmetic, meant to convey the security that had been present. Radios, S-Navigators, ballistic vests (perhaps on an armor rack), perhaps some playing cards strewn about, a gas mask, and other utilitarian tools might be found there. In the office (end-game) room, you would a find a clean, orderly room with no firearms available, and some other general items reminiscent of the first room - sort of as a resupply area.

Because each of these rooms are such gold mines, as a general rule - one per sector. That's it. Thoughts?

I don't know. I think that those locker would make the game too easy as the players don't use all the items per sector.