I've managed to get the nanomesh textures to show up, but unfortunately, the upper armor textures don't want to show up. The texture folder for the armor shows there's nothing there in Nifskope, but when I open it in file manage, they appear.
Final Edit: I got it to work. Turns out I was missing the Halo 4 folder that the Master Chief textures go in. Who would have thought. Once I put the Halo 4 folder in, everything went smoothly.