If I remember correctly, part of the problem with Poser Pro and Vue7 was that Poser Pro saved the paths to textures etc in a different format as earlier versions, and this problem was being  adressed by e-on. I don't know if it has been fixed yet, as I don't use Poser Pro.

<<I have been using Poser for some time now and last year upgraded to the most recent version of "Poser Pro". >>
I take it that this means that you have a previous version of Poser? If so, what version? 5, 6 and 7 can use Poser shaders, and work with Vue7.
The major problem is the green tint that appears when using Poser shaders that have a non-white diffuse colour. Some shaders use white, others tend to use a very pale blue.
For the ones that use a pale blue (Poser) diffuse colour you can get relatively good results by changing this to white (as a workaround until the problem is solved), but so much depends on your lighting and atmosphere anyway. The shaders that already have white as diffuse colour seem to work ok.

2 - I seem to remember that Dave Burdick had a fix to use his SkinVue6 in Vue7. Sorry, don't know where, and haven't tried it out. Similarly, I still haven't tried SkinVue7 so can't comment on it, but I can't find the threads that you were referring to at e-on.  ???

3. figure renders in PoserPro and background in Vue??????   - don't do it. Your lighting and shadows won't match without a LOT of postwork. 

Rob