Ok, here is a roundup of everything I have tried for those attempting and failing still and where I'm at now.
First my hardware:
nMP 6 core, 512gb hd, 16gb RAM, D500s
MBP mid 2010, i7, 8gb RAM
Toshiba 1TB USB3 external drive
WD Black 4TB internal drive in an Anker USB3 dock
Lexar 16gb USB2 flash drive
windows 8.1 core (legit copy provided by a friend from microsoft)
First I tried to install bootcamp like normal. I set up the install disk on the lexar went through the whole process and got the error message "cannot update boot configuration" before the first restart
I tried again using the toshiba (lent from a friend)
Same error, though this time it gave me a window after language selection before the activation window with an install button and a repair compute button in the bottom left corner which did not appear on the lexar
Then I tried to format the drives with disk utility rather than letting bootcamp make the partition.
I first tried formatting in exfat as a walkthrough suggested and the advanced install options in windows was unable to format the drive, something about MBR format.
Then I tried making empty space and formatting the space with windows. This created a reserved partition of 128mb and the rest was for the OS. Install, same error about boot configuration. Now I can't remove the partition with bootcamp, so I remove it with disc utility, but disc utility can't see the 128mb partition and won't expand the OSX partition. I then had to go back into the install menu and erase the reserved space before OSX could repartition.
I then tried winclone. I setup a bootcamp partition of 100gb on my MBP. Got it set up without bootcamp drivers and followed winclone's instructions to the letter. Generalized the os, saved it to the toshiba. Moved it to the nMP's HD, partitioned, restored to the partition. Booted into windows. Windows then gave me text saying it was setting up devices with a percentage. It hit 100%, said getting ready and then said that it could not set up windows to run with my computer's hardware.
I then tried to winclone to my external WD drive. Came up with error code 0xc0000001 missing system32\winload.efi.
Then I tried the long method provided by kfscoll. Booted a parallels vm on my nMP, went through the whole process of building windows on the toshiba. Loaded it and got the same error message about not being able to run with my computer's hardware. Tried again from scratch (as getting this message once ruins the os) and tried to boot it on my MBP, same error.
I then opened my bootcamp on my MBP and went through the whole process again on there, tired booting from the toshiba on my MBP, same error.
Then I saw the solution to the missing winload.efi message kfscoll posted and just tried doing that with my WD drive. I did not have a ESP volume, so I tried it with the EFI volume, same error about missing file, I tried again using my MBP bootcamp to access the files, same error.
The good people at apple are holding the party line that 8.1 is not supported and that whoever got it to work "may have been using other methods," which is bs of course, but he probably doesn't know that.
I acquired a version of 8.0 and attempted to install that with bootcamp, but I got to the drive formatting section and windows told me it couldn't find the partition and wouldn't let me install.
I am waiting for my microsoft friend to send me 8.0 and a good CD key and I'm going to take my machine and my iso to an apple store and ask them to install it for me, let them suffer with this issue for a bit.
If anyone sees any errors in my methods, I'd love to hear it. I've been at this for days now, all the power is tempting me to play some high graphics games and I can't and it's making me sad.
For those of you that had success easily, I sincerely envy you. Get some headshots for me!
