Quote - Do I leave these files alone or pull them into Photoshop and change to black and white?

Leave them alone, Poser will connect them to the "Gradient_Bump" channel.
(There actually is no way to convert BUMs back to the original B&W, see -> http://www.morphography.uk.vu/bumpmaps.html)

Your fuzziness may be due to Poser's texture filtering or to high a shading rate.