You have come across probably the most problematic area of Linux, multimedia. I don't use SuSE anymore but you will need to try a couple of things. The first is the sound issue.
Using YaST search for 'alsa' (advanced linux sound architecture) and install it. That may help with your sound problem.
DivX is a problem I think but you will need to install Xine and the codec library to get to play more video formats. If I remember how to do it correctly, it goes something like this:
1)
http://packman.links2linux.org/ and seach for Xine.
2) Find the xine-lib for your build, i.e. 9, 9.1, 9.2, 10 etc., right click and save link as, perhaps to your desktop or where you can easily find it (you will need the full directory location later)
3) Open up a terminal, form the Menu bar > System > Terminal > Konsole and switch to root user, you will need your root password for that.
4) Change into the directory where you saved xine-lib and type:
rpm -Uvh xine-lib
After it is downloaded and installed you should find that Kaffeine will be compatible with lots of video codecs. Please note, some of the WIndows codecs will require other libraries *cough* libxine *cough* but I didn't tell you that. (same process of install)
I hope that helps, I am not a Linux expert and if I have made a mistake I am sure someone here with better knowledge will be able to help. If you haev no luck you may want to consider Ubuntu,which is what I changed to after suffering similar problems as you. With Ubuntu noobs (like me

) can use the Automatix script to download and install lots of cool stuff including video codecs and WinRAR support easily.