Try this, replace Config file, add SSDT-xx to Patched folder. Remove SSDT-HDEF.aml from Patched. It has layout-id set to 13 yet you have 14 set on your Config file. So it's conflicting.
The added SSDT-BRT6 might fix the Fn+F11 and Fn+F12 Brightness issue
The config is now setting audio to layoutID 21, if it still doesn't work, then switch it to 56, that should work.
If that still fails to grant you audio, you might want to remove FakePCIID_Intel_HDMI_Audio.kext from /L/E
7280_AudioFix.zip