Have you seen Jan Buelen's "Hardware Independent Imaging - rev 9.1"? This has helped me a lot (and I am sure countless many others).
I am having problem configuring PCs with AMD + NVidia components (Lenovo A60) where the base Image was created on a PC with Intel components. I do not know, at this point, if it is even relevant, but one of your steps...
Remove driver location details from reg key [hklm\software\microsoft\windows\currentversion\devicepath]
...may be helpful. I'll test and post back.
Anyway, my problem is, I am getting BSOD with 7E code (or 7B, very hard to read on the split-second Blue Screen) after post image reboot (before Mini Setup). I suspect it is related to non-Intel SATA controller (MSD) driver. ...but I'll put my question on a new post.