You can enlarge the production frame in your render settings -- enlarging the render size will correspondingly enlarge (or at least reshape) your production frame. As for seeing more things within the production frame, you can either dolly the camera away from your subject, or change the focal length of your camera to a wider angle (smaller number) in the Camera Properties tab. As for moving things back into your view, I don't think there's a way without either selecting the object and typing in new coordinates, or opening a second view pane and sliding the object in from the second viewpoint. Once it's outside of your view in the window, there's no real way to grab the object and drag it back in, unless you happen to be able to see the projections of the object on the working planes. Hope that's helpful. - Dex