Renaming your user folder will break both obvious and non-obvious links, permissions, and registry keys. In the future, you can refer to How to Rename a Windows 7 User Account and Related Profile Folder (essentially the same for Windows 8) or similar guide to rename your account through the proper APIs, giving everything a change to properly update and reconnect to the profile.
Check permission differences on the shortcuts. You can also use a tool such as SysInternals Process Monitor to watch the folder in order to check for any errors as the shortcuts are being enumerated. (Specifically, run Process Monitor, set it to monitor your Taskbar folder, then kill and restart Explorer via Task Manager. Capture the results and look for errors in file system accesses.)
Even if you solve the Taskbar shortcut issue, you are certainly going to run into various problems ongoing, and some may be much less obvious than others. Renaming system folders is like moving out of your house and leaving no forwarding address. You may update all the obvious contacts with your new address (changing the registry settings), but those people who contact you every six months, or once a year end up looking for you at your old house and giving up (for example, NTFS reparse points that are now invalid).
If you want to pursue this path, I would rename back to the old user, then follow the instruction to Fix a corrupted user profile. This will give all the various modules a chance to participate in the rename/new profile.
As this was a result of following the steps in How to rename user folder in Windows 8?, I would not recommend that approach.