As far as editing textures, if there is a plus sign to the left of the poser object, just click it to access the different material groups. Then find the one you want by clicking on each one until the one you want is highlighted. If there isn't a plus sign, then you can't obviously. I always save to pz3 to export to vue, and I have always gotten the plus sign. My guess is that if you aren't seeing the plus sign, you are exporting it as .obj.

Version 4.06 has only been out for a few weeks. Click on 'Help/About Vue d'Esprit' to find out for sure whether you have 4.06. It is quite possible you have an earlier version. If not, download the upgrade. It might fix some of your problems.

As far as times are concerned, I have seen some renders that take 6 or more hours. It depends alot on lighting, and polygons. To me, 7 million polygons is a lot. I haven't done anything complex, but my most complex scene only has 509,068 polygons.