Actually in the games you've mentioned, although they may not use BSP - they'll still have a pretty similar Visible Triangle Culling routine, which will no doubt have been pre-compiled before hand.
As for the shadows, they're either done using stecil buffer or a pre-calculated lightmap ... please understand that shadows for worlds ARE NOT shadowmaps, because shadowmap retains to the shadow underneath the character/world objects which are usually simple circles or squares which are blended onto the worlds texture.
Lightmaps are what are combined with the textures which give colour and shadow/light to worlds based upon the Ambient Light... they are the best way to save processor speed from using Point Lights, which you can use however more than 8 and really you'll need a very powerful graphics card! Also it should be noted that you calculate the Lightmaps from the Current world light points and not the 3d packages light points because it will not produce the results you require for a game world!
With all of this you are just jumping into the deep end and there really isn't much point - i mean these are sorts of things that should be asked about ONCE you have a working demonstration version of what the game is. Even then should be thought of as upgrades.
If you are serious about adding these things then there are plenty of C/C++ tutorials for them, if you can't adapt them or understand atleast the concepts to develop your own then i'd forget about it!
To be honest i haven't much of a clue of kind of game you are going for which requires the Vis of an Outdoor style game, the bump mapping and pixel textureing of Doom3 and Lightmapping to boot.
I would suggest you carefully develop each feature you wish to include using online tutorials as a base, THEN possibly add them all together - but to me unless you're one diva of a coder (which i'm highly doubting right now) there isn't a chance in hell this'll run on anything but my rendering machine ... i don't think many people have the better half of $5k to spend just to play your game!
You haven't even displayed any work here yet ... which kinda makes me even more wary about giving you any sound advice or true code to work with, no point in giving the man the muel for his cart if he doesn't have the reigns to control it!
Anata aru kowagaru no watashi!