I'm not sure how to improve performance but I do know how to get the sound to work. In order to do so, you will need to download Wine for mac. Once you have this, click the wine bottle icon at the top and select change prefix. Now go to the prefix where the name of you Call of Duty - World at War bottle (my bottle was named CoDWaW so I selected the prefix CoDWaW). After changing the prefix, click the wine icon again but this time select winetricks. When the window pops up, type in win7 in the search bar. Select the second option and press okay. This will turn your CoDWaW bottle to windows 7. Now exit out of wine and launch Crossover Games. Go to the control panel for your CoDWaW bottle (it is accessed via configure-manage bottles) and double click on wine config. When the wine config opens up, select the applications tab, click add application and find 'codwaw.exe' and 'codwawmp.exe'. After adding these applications, click on the thing next to 'Windows Version' select widows 7 for both and hit apply. Now when you restart the game, you should be able to hear sound.