You can change the intensity of lights added in Vizard. In terms of detecting the collision with the torus, are you using desktop navigation or real tracking to move the viewpoint?
The introductory tutorials in the Vizard help are a good place to start if you're new to Python and Vizard. I would also recommend looking at Teacher in a Book, available from our
downloads page. It includes a good example related to lighting a scene and a light demo which allows you to modify the different parameters of lights and immediately see the results.