Try the aux camera. It works like a camera mounted on a turret. The main camera always revolves around the world center. Another trick I use is to create a simple sphere prop and call it CENTER (so I can see it easier in the heir editor). Place it at about the center of the world so the floor is alingned such that if you dropped the sphere to the floor the world floor would match. Then make all world set objects children of the sphere. Now, instead of moving the camera, just move the CENTER and place the whole world around the camera. Works way better than trying to move the camera through the world. Just hide the prop when you're done moving. Also you can move the entire set to something like y=10000 to set up all your figures without the set slowing down your preview. When ready just move the sphere back down to y=0. Also use the ctrl-8 shaded poly preview mode instead of textured preview. After a bit, poser will just drag trying to keep up with previews.