Another thing is that shadows take forever to render.  From what I can tell of your light
control panel, you have 14 spot lights, each with ray traced shadows.  And there are a lot
of things in your scene.  So for every object in the scene, Poser has to calculate 14
different shadows for it.  So do you really need every single light casting a shadow?
Or could you maybe cheat and just have a few lights casting shadows, like maybe
the brightest lights or lights where there is a particular emphasis on certain objects.
Or even more drastic, do you really need 14 spot lights?  Perhaps maybe an infinite
light here or there would be sufficient, with again spot lights on objects you want to
emphasize.