Here are my suggestions for making the game as "modern" as possible without changing a bunch of core game functionality.

For module installation, you can make your life * a lot* easier by using one of the mod installers out there. I personally use NWN Installer:

http://casualcoders.com/nwninstaller.html

This will place all of the files in the correct locations; it will also make uninstalling easy. If you use a lot of mods, this is especially helpful as you don't need to remember which files go to which mods.

Also, take note that the CEP is pretty much essential to use most of the fan-made modules out there. New content is added all the time, and it comes with an easy-to-use update program.

I'll also put in a plug for NWNCQ. Take a look at some before and after screenshots - the new graphics it provides are much better than the originals. I wasn't able to get the installer above to work with this, though, so this one you'll probably need to install by hand by placing it in the overrides folder.

Finally, you'll definitely want NW Shader as well. You can turn various features on and off to match the capabilities of your computer hardware. If you've got the horsepower for it, I'd turn on SSAO. This is a lighting feature found in modern games like Crysis that really does a great job making the scene look "deeper" in terms of the lighting. You can read a description of it here:

http://en.wikipedia.org/wiki/Screen_Space_Ambient_Occlusion

It can really tax your computer's resources, but I've found it to be one of the best things in recent years to make NWN feel like a newer game than it actually is.