1) Which is exactly why the process appears to hang for hours because it can't write to the NTFS drive. I performed a dual boot install with a FAT USB drive and didn't even notice the windows support file download, it took less than a minute. Then a week later I decided to update to Win 8.1 to performed the process again, but forgot that in the interim period I had reformatted the same USB to transfer a large file, for which I needed to format to NTFS. Oddly then the windows update seemed to be taking forever. I cancelled bootcamp, reformatted the drive to FAT, began the process again and hey presto, virtually no download time.
2) Apple's servers have nothing to do with it
3) Hard as it may be to comprehend, people still need help when attempting this procedure for the first time and this thread was top of the google search when I needed help performing this procedure myself for the first time.