just a bit to say: but lessening the bump isn't really the answer.  it's not that the bump needs to be less, but that it needs to be less defined.  there's a big difference.  again, it's in one of the linked documents.  it also shows the blurred edges (like the nostril, edge of the lips, etc.), and it's lack really keeps Poser items looking worlds less realistic than anything else that has true SSS.  at least when you render at the resolutions i do (2400px+).

as for exposure, etc., i'd say if you're talking about adjusting curves, gamma, or levels then you're talking about the transform (GC, sRGB, or whatever).  i suspect that just about any adjustment you could make to the color space in Photoshop you could do with nodes because it's basically a mathematical transform.  you might show screen shots of the adjustments you're making, because bagginsbill might be interested in building that kind of adjustable power into the shader.