Gsm and wimax isn't put into the rom so that is the issue with it not being there. When more stuff is fixed those will be added till then they won't be. Voice should and will work on boot as I test that when the mic was fixed for speaker and regular. Voice search should also work on boot if it doesn't I am not sure but isn't rom related. Apn should stick though the apn is in the rom for all 3 carriers. The build.prop needs edited for the correct mnc numbers for boost or sprint for the right apn to load. Branding is because the builds are for my carrier, where to change it you need to if I recall add the right eri to system/etc or add it to the framework-res.
As for the boot sound sense supports it and not sure on this. I don't have time to test it nor is it a feature of cm10.