I've been playing both NWN 1 and 2 since they came out, and already know how mods and custom content work and how they can possibly interfere with each other. So why should I ask her? Especially when this is about something you said.

You claimed, that the authors said, that you shouldn't install any other mods at the same time, period. However, like I mentioned, I can't find such a statement by the authors at all. Nor does it make any sense. The problem isn't other mods, but custom content within the Override folder. Which the authors have clearly stated.

Custom content within the Override folder can cause script-failures and other incompatibilities. Therefore, installing mods which require them could cause problems, depending on the type of custom content. However, other mods will work fine. Also, there is a lot of custom content out there, which is completely independent from mods, like Kaedrin's PRC pack or Reeron's Spellfixes. This means, that people can run into problems, even though they never installed any other mod.

Ahhh... An Elder Scrolls player? Welcome!

NWN modules don't work that way. You can install as many mods as you want, but modules in NWN are "Stand Alone" adventures.

Let's start here:
In NWN, all modules are mods, but not all mods are modules.

In many moddable systems, most notably "Elder Scrolls", "mods" are "inserted" into the main campaign.

This is not the case with NWN. There are "mods" that can be inserted into your override folder that will effectively change all your "modules" including the main campaigns. These might change your font, your voice sets, your music, your portraits, various model appearances, etc. These mods CAN conflict with each other. Always back up your old override folder before adding new content to it.

Modules, like BG and IWD, however, are different. They are installed into your mod folder. Each module is an independent mission, adventure, or campaign. You can export your character during or after one module and use that character to start another, but you can't actually "play them at the same time".

Modules often require Haks. These are files that do the same types of things that overrides do... and a LOT more. Haks can add completely new and unique content (custom models, sound files, etc). Don't shy away from haks. Because modules are free-standing you don't need to worry about conflicts like you do in systems like elder scrolls, and haks provide the kind of unique content that really lets modules stand out!

Now... if you want to go all toolset ninja, on the other hand...

Muahahahahaha... Things get a little more complicated for builders, but ANYTHING is possible.