Trashman ... I had a chance to download the demo, and it all looks pretty simple really.
Models are in DirectX format, with a .X extension. Textures are simple bitmaps. ll the models in the demo are pretty low poly, and use only a single texture. The player model is the only one with a 'proper' UV map.
I would assume that the rest of the ship details lie in the 'DATA' folder, which has encrypted txt files that I can't read. I don;t think there is any way the model format would hold info in the sam way that a POF file does. POF (as with a lot of game specific model formats ) is doing a lot more than just holding hte geometry. These just hold the geometry. You can open .X files with 3D Explorer.
Most of what you are asking about won't be all that relevant here. You could easily hold weapon positions, types etc. in a text file with just the physical polys in the model.
In theory, anyone could build models for this.... just not the code to make them act differently. I have a few 3D apps that will write out .X files, or you could convert them using 3D eXplorer
Additional:
Am I the first to mod the game
... I converted one of my WIP Homeworld ships over to .X and swapped it for one of the demo ships.... works as expected
Gunfire comes from where it did before. Just changed the physocal model. Rendered it quite nicely
