Moving desktop folder back to where it should be!
Having a bit of trouble following your description of the situation. It'd be helpful if you used actual path names instead of "The one in my user folder" type descriptions.
You have a backup right? Ok then...
The sidebar link is just a shortcut, so it doesn't really mean anything by itself. Fix that last. Just delete it and then re-add it.
Run a disk check and permission repair if you haven't already.
If ~/Desktop
doesn't exist and you're sure it was some how renamed .tsclient, use terminal to move/rename it back. I think its more likely that your ftp client uses that as a temp location and that the files there are only partially downloaded though.
If ~/Desktop
does exist then just move the folder contents back where they belong not the folder itself. Then delete and re-add to the sidebar