1) Compiz is a Window manager and a compositor. OpenBox is a window manager. You can have only one window manager and only one compositor at once. So you can not have both OpenBox and Compiz at once. Compositor compatible wih OpenBox include xcopmgr, Unagi, Cairocmgr and a few other.
2) Compiz development now focus on Ubuntu. Most distributions stopped supporting it. Compiz is a little problematic and not very forward/backward compatible. So having it at this point in time in something else than Ubuntu is more complicated then it used to be.
3) xorg.conf is deprecated. Most of the configuration is now done automatically and unless you have a very special setup, it is not needed anymore. The configuration is either non-existant or located in /etc/X11/xorg.conf.d/. While xorg.conf is still working, the one you posed above is clearly not a complete configuration file. So I guess, if the issue is driver related, it will be part of the dynamic config or the other configuration files.
4) The information you did post is not relevant to help solve the problem. If the problem is not caused by any of the above points, then you will need to post the error. Not just "it does not work". If X fail to load, then you probably did something wrong. Undo the chnages if you can (if you created the xorg.conf, then delete it). What is your graphic card? What is your debian version? Have you installed the right driver, if yes, what is the version? Take a photo of the error when xorg fail to start. With so little information, there is little we can do.