Hey thanks for your in depth reply! :)
The idea with using a higher poly model is quite a nice idea. I guess you did that with the base nude texture (I noticed that it's quite detailed in 1024px but seems to be downscaled and then upscaled again with bilinear filtering)
I have quite a collection of skin textures (reference sets of real humans from 3d.sk ) and tried to texture paint them onto models, but it's a mess (because of the lighting in the images) unless I base paint everything with a tiled skin texture first and then use stencil masking to apply the details like eyebrows, elbow, nipples, finger details and so on.
I will try to bake a highres model :) The next annoying part will be the hairstyle x_X