I'm not getting blurry pixelation in the CS.
What is your clamp mode & Filter mode set to?
I was going to ask myself, as these are about the only settings you can tweak, but if you create a new NiSourceTexture in NifSkope, it will default to CLAMP_S CLAMP_T, rather than WRAP_S WRAP_T and FILTER_NEAREST rather than FILTER_TRILERP. They are usually about the only things you can tweak on most Texture nodes apart from the PS2 settings, which are irrelevant.
In case anyone doubts, Morrowind is at least nominally capable of dealing in some way with all these maps. A string search through the exe finds all these map types defined.
EDIT: The one I'd love to get working is gloss maps. These are incredibly versatile, allowing even a mediocre texturer to produce dull leather, shiny leather, pvc, plastic, dull metal, shiny metal and masses of other effects, just by changing a simple light map and a simple gloss map. In the hands of a skilled artist, they are even better!