FINALLY!!!! SOME ANSWERS!!

But yeah, with the 3rd, I wanted to create a ship that would carry a bunch of frigates in its own hull. It could then load and unload these frigates at will. Maybe Sins 2. Or even something else, hehehehe.

EDIT: looks like I'll just have to try and use frigate meshes on squads instead. Oh well.

Sadly, I will say I'm not entirely sure of this, but from what I've noticed of tangent maps, they're sort of like a texture (for lack of better comparison) that defines HOW the model reflects things, should it be reflective at all.  So if you load up sins, and create a ship you know is pretty reflective, and just look at how those reflections look in the game as you move the camera around the ship, then go and alter the ship's tangent map, when you load it up again, things will look different.  It certainly effects shields, since all they have is a tangent map and no textures. 

Now, again, I could be wrong about that, or that could just be only part of what they are.  But it's just what I've observed with playing with them while making ships myself.

 

For your number 2, StCobalt's links are pretty useful.  I know less so for the second, since I don't use 3ds max, but the channel guide for the different .dds files should help you a lot on that first post.

In the ForgeTools 3\Documentation\Modding_XSItoSins_ModdingSupplement.pdf there are instructions that mandate you create a tangent map for all models, with the suggested method utilizing a duplicate of the existing UV mapping. I have done this and the meshes work, but I too would love an answer as to WHAT THE HECK it is I made and/or how it affected the model.

GIMP with the DDS plugin can open and save the .dds texture files directly. When you open the file, tell it to NOT load the mipmaps (I do not know what those are, but Sins does not appear to use them). If you want to make a ship black, open the -cl.dds texture file (this is the diffuse color map); the selection tools and shortcuts and the paint bucket work like in Photoshop (IIRC). Select the area(s) you want to be black, then use the bucket fill tool to dump black in them. If you need the ship to be more reflective afterwards, then open the -da.dds texture file (this is the data map and includes lighting effects) and add to the BLUE CHANNEL (blue is how mirror-like that area is; red is how shiny it is). For more info on which channels do what in which files, see As promised a proper tutorial guide to edit sins textures.