Just to get back to square one, what are the contents of your Data folder that used to be at the top level of your iMac but is now on your desktop?
These data are MY data. i.e. various documents I have accumulated over the years and which I must keep.
If I'm correct, you've got two options: You can either leave it on your desktop or create a new folder in /Users and populate it with your data.
That would be preferable, particularly if it helps applications 'find' the Data folder. Right now I am having to save documents to the desktop and then Drag & Drop into the Data folder....a giant pain.
As the Users now reside on the hard drive, and I can't Drag and Drop to the hard drive, how would I get the Data folder to a folder in Users?