I think it may be the ambient color getting exported with the texture.....
under the world tab, my zenith and horizon colors are 0.42 0.42 0.42 gray, and mine is really dark. See if yours is 0 0 0 white, if so, then that's probably the problem. I haven't experimented with the tools since I posted this thread. My ambient is 0 0 0... but as you can see, the material recieves .5 of it... not sure right now why mine is so dark, and your is so washed out.
RE: SDK
I think, Firaxis may not be allowed to release any tools, under the contract they have with Gamebryo. I also do not believe there are any plugins for .nif tools unless you buy the gamebryo engine. There is very little information about .nif tools on the net, and what information I could find said gamebryo is pretty proprietary about them. This is not uncommon for th eindustry, and the only attemtp ever at bridging modders, games and 3d software was gmax, for 3ds max, which was cancelled.
That means open source may be the only hope. And right now, there are no max tools, but niftools also has a maya exporter, allthough it is not as advanced as the Blender exporter.
I really would not consider this "hackery", since it can't get much simpler than a 3d program and an export script. (except maybe if blender supported .dds files, so its 3d program, export script, and dds convertor).