Script syntax looks good, but I have a few questions:
-- Do newer Wine versions (e.g. 1.8.2) not work for this game? They're more likely to be installed by another script, and often fix issues, possibly including the one about sound.
-- Is dxfullsetup really necessary? Newer Wine versions have a pretty good DirectX 9 implementation, I think.
-- Is start /unix necessary? That can lead to issues. It's better to just use POL_Wine_WaitBefore and avoid start /unix and POL_Wine_WaitExit.
Otherwise looks good.