1. You can change to MacPro7,1 in the
config.plist file but you will need to generate new SystemSerialNumber, SystemUUID, MLB, ROM, SMBIOS because if you do not, macOS won't be very happy. These settings are located under
PlatformInfo >
Generic section. Use
genSMBIOS utility or
OpenCore Configurator app to generate what you need. No need to re-install macOS.
2. To use the built-in WiFi and Bluetooth, see this
post
3. SPDIF is not working and a lot of people are having problem with that
4. Search is your friend; it's located at the upper right corner of this page. Use it to your advantage because it is the best way to learn