BDA - Putting it all together

I finished the preliminary textures for all the armor pieces (diffuse, specular, normal, and glow). However, they're a bit too clean and don't quite look right. I was going to work on dirtying them up, but I ran into yet another issue with the armor.

The issue? The same .nif that produced this:

Is now, months later, producing this:

The torso is way too dark.

I made a backup of the .nif while I was trying to get rid of that viewangle clipping issue (still not fixed). So, aside from a name change and a defrag, the file hasn't changed at all since that first screenshot. No amount of fiddling with the first "working" .nif makes it light up normally (despite what http://wiki.tesnexus.com/index.php/Skyrim_common_mod_issues tells me).

I tried exporting to a new file and got this:

The glowing polygons all move with the body, but the main torso won't.

The skin modifiers work in 3ds Max, but when I export, only the glowing polygons work. Exporting just the main torso doesn't work at all. It'll only show the t-pose. Even after fixing up the body partitions, vertex color flags, UV set number (4097), Unknown flag (8 -> 0 and vice versa), Has Normals flag, using existing LightingShaderProperties, and Updating Tangents, nothing works.

I can import the nif into 3ds Max and it'll deform. If I re-export it from there, the model moves with animations, but is permanently black. No manner of tweaking fixes it.

I've already installed and reinstalled different versions of the NIF exporter and, from the initial viewangle clipping problem, even tried a completely different machine and version of 3ds Max.

I'm pretty sure both are deforming

If anyone, anywhere, knows why this is happening, please, I implore you, tell me why. Tell me what critical thing I am missing that causes me so much grief whenever I try to weight a model for export to Skyrim.

The Bassrath-Kata Bow, the Duster, and now, the Blood Dragon Armor set. None have gone smoothly.
The Bow resolved itself with a bit of fuss, the Duster still has random polygons shoot off into oblivion, and the Blood Dragon Armor won't let me export the torso properly. The boots, helmet, and gloves exported like a charm, but the torso? No no no no, can't have that now, can we?

Edit:

My export settings:

Second Edit:
The T-pose issue: SLSF1_Skinned became unchecked. "..."
Still no idea what's going on with the viewangle clipping or why the Duster randomly spazzes.