Alright, I'm still working on this shader, and I just corrected a majot bug!

I was calculating the tangents incorrectly. This means that the faces were being lit corectly, but the bumps were getting the light direction incorrectly. I have fixed it now. It's hard to tell the difference, but it makes a big improvment in look when you figure out what to look for!

I still need to fix some of the lighting options, then I'll update the download and let you all know!