Mac Pro keeps rebooting when installing Win7 on Mac Pro using EFI Boot/GPT drive
"Windows 7 x64 (64-bit) will NOT boot natively using UEFI on a Macintosh!"

See source with technical details here:
https://darobins.wordpress.com/2009/10/04/native-uefi-windows-7-boot-on-mac-mini/

PS
It would have been nice to not only copy and paste my installation guide in your question. That cost me some time to put online. A link or reference as source would have been nice. From the title of my post it could have come to your mind as well, that a WIN8 or WIN10 installation had been the goal, not WIN7...EFI Boot Windows 8.1 or 10 Install on MacPro4,1 / Mac Pro (Early 2009)