@doobre
~/.config/gtk-3.0/bookmarks
is the same as
/home/username/.config/gtk-3.0/bookmarks
(~ is a shorthand for the user's home directory)
Yes, you can take a look here how to do this. Important is not to format the home partition.
When you plan to install other versions of Zorin, e.g. Zorin 18, there could be problems because the gnome version isn't the same.