Quick Launch would be super easy to transfer, since it's just a folder of shortcuts.
Start Menu favourites and Taskbar pins meanwhile might be complicated - it depends on if the respective folders contain stuff that is no longer pinned, too, or not. If they do, it'd need to rely on #3 and also a discovery being made to decode the hexadecimal storage format to readable paths.
Irregardless, both would also need a shortcut-to-application index to be introduced, in order to translate the paths discovered to applications in the Feren OS Store