From your post, why would you set EthernetBuiltIn to no?
I set my boot.plist to GraphicEnabler No and profile to Mac Mini. I can now boot to OSX with the 7950 installed, but I'm stuck at 1024x768 resolution. That is not going to cut it.
How did you extract your device string?
I think someone may have found the exact solution I'm looking for. I'll try this when I get home today.
http://www.insanlynac.com/forum/index.php?showtopic=282631
First try just injecting the EFI string from the link, you can save a lot of time.
Will do!