Can't install Windows using Bootcamp after Yosemite Upgrade

I upgraded to Yosemite recently and all of a sudden couldn't boot into my Bootcamp partition. After spending hours trying to find the solution, I cut my losses and tried to reinstall Windows in Bootcamp only to find that it now won't even complete the installation. It goes through the Windows Installation process but when it reboots after "Complete Installation", I just get a black screen every time. I reached out to Apple Support and, while the guy was patient and helpful, he put me through the exact same process that I had been following, and didn't stay with me long enough to see it fail AGAIN.

On Loner T's advice, I've created a new thread and pasted the results of the diskutil, gpt and fdisk commands below ( I took the actual commands from Re: Bootcamp and Yosemite upgrade - potential data loss warning) :