Here is the method I use in Pose4 to get rsr thumbnails that display transmaped objects, background colour, etc. This method presupposes that a poser square will display properly in Texture Shaded mode.

Set-up, and render your scene 600x600 or larger, leaving a little bit of room round the edges for cropping, and export the picture. Set-up a poser square from the Prop Types pallet in front of your scene so that it fills the window, (just move the square and/or the camera, not the thing you want to save to the pallet). Load the picture you saved into the square as a texture, and adjust the lighting if necessary (it might look pretty crappy at the moment, but should look OK at rsr size). Now use the dropdown list under the render window to select the thing you want to save, and save it to the pallet.

Your Pallet will contain a picture of the square in front of the camera with the rendered image on it.

As far as your problem with wire frames around objects in Texture Shaded mode, the only thing I can think of that would cause that is if the objects had been saved with the "Element Display Style" set to "Lit Wire Frame". Poser can display diffrent elements of the scene in different display modes, and it sounds like that may be happening here.

If you could post a screen shot of your display it might help diagnosing the problem.