The issue which confounds moving shell User folders is that Windows 7 Backup Imaging then wants to include the data drive in the System image since those are System files. But if you use another imaging app then it's not an issue.
I also had unsolvable permissioning issues when trying to run installers from my User Downloads folder on another partition but I've not seen others complain about it.
Kari has had reduced participation here due to health issues so may not be aware of it, but Brink is as it pertains to his popular tutorial User Folders - Change Default Location
and is giving the same alternative to use Libraries lately from what I've seen.