I got no experience with Intel GMA950 so I cant be of much help there, the other poster said he needed an SMBIOS enabler and/or maybe a custom DSDT to get QE/CI working.
About sound depends on the kext you are using for it, VoodooHDA needs some other dependency kexts in /Extra/Extensions. A patched AppleHDA.kext should work as it is but I dont know for sure.