On the eyebrow thing, I think Seraphira was using something along that line as well, with the "Multiple Layering System" she was putting into her Project Kaimira model ... which was fantastic. I think she had posts on it in the Developer's forum around 2004-2005, and it had quite a few additional layers over the skin for tattoos, details, etc.

She lost the whole deal in a hard drive crash due to a virus. Pity, too, because it looked really promising.