I have a question for you dev folk, are things like railings, pipes, light fixtures, and various other nick-naks models that are already in the sandbox??? Or do I need to make every little one? 
That depends on how unique you want the model to look. Its perfectly ok to re-use crysis assets to detail it if you really desire, it just means the model wont have a completely unique look. Ideally, you would model the majority of them youself in a modular fashion.. ie. a set of railings, 1 or 2 mtrs long with a couple of different corner angle pieces and end pieces(maybe 6-10 "bits" all up).. then just copy/paste them around where needed(make sure u uvmap and texture them first though lol).. you can do the same thing for most of the indoor detail bits.. computer panels & screens, floor & wall panelling, stairs, doorways/hatches etc.. .. alot of the detail you will be able to normal map rather than model, floor and walls, roof etc.. anything that you need to add detail too, but not change the silouhette of, is usually an ideal candidate to be normal mapped..
Texturing that beast is going to be an undertaking and a half though.. being so large and with such a large surface area means that using a unique unwrap for the majority of it wont be possible, it will have to be setup to use tiling textures so a couple of smaller textures can be tiled over its surfaces to provide the resolution required.. using blend materials in max with some clever vertex painting can yield some nice looking tiled texture surfaces(which can easily be RTT'd out to use as a diffuse).. combine that with some decals and you should be able to make it look really good aswell as unique.
NOTE - A "cheat" for getting some of those detail pieces looking unique quickly is to export them from inside the editor as OBJ models( File Menu->Export Selected Geometry... ), then pull them into max and retexture them/tweak the geometry to look how u want.. any "Brush" object can be exported from sandbox as an OBJ, though they usually require complete remapping of textures as the uv's get all skewed.. it also exports the collision helpers but stuffs them up so they need to be deleted and remade most of the time.. you cant export anything that isnt a brush.. so entities wont export, animations wont export etc... basically, if you can place it on a map as a "brush" you can export it as an obj.
This method is not ideal though, as you wont be able to use the model in any other engines without breaching copyright, and you also wont be able to claim "complete" creation of the model for use in a portfolio or anything..
Also, check ur pm's I just sent you a download link to a PDF that I think will be quite helpful to you.. it covers all aspects of creating models in 3ds max for games, modelling, uvmapping, texturing(including baked and photsource normal maps and how to combine the 2 properly) aswell as how to create LOD geometry in the proper manner(ie. NOT using "multires" or "optimize" lol).. pretty much covers the whole slew of topics that are involved in creating models for games.
