One reason for extra textures loading in Poser is material groups in the figure that are not used. They have presumeably been created during figure development and not removed .  When you go into The Material Room and open the list of material zones the Preview,Default and any others below these in the list often call up textures which are not used but are loaded every time you use the figure.    These textures should be deleted, or even better edited out of the CR2 file and the figure resaved to your library.