well if i made an inventory thing like said, you would need it to hold your items and such, wouldnt be very handy if you couldnt say.. use an item when you really need to, or switch guns, or combine some herbs, use a key, or so, when you realy need too, because theres a zombie nearby..
safe rooms will have something similar though, players will be able to store items in a box, (which will come onscreen, like an inventory thing), all save rooms can access the same items, so you can store items in there for later use instead of carrying around, players will share so if a player leaves or dies, items they put in are still acessable to other players.
files and manuals and other sorts you would get in the game inventory, are going to be on quests.. incase i havent said yet, it seems the best place to keep them.
Maps.. im not quite sure yet, i think chainer came up with an idea of an image of it the map somewhere on the map that your screen looks at when you want to look at a map, but if anyone got any ideas for that, id like to hear them please

thx