If Export/Import of connections is all happening on same PC, you can just copy Connections.XML from the old version's user files folder to the new version's user files folder, and password will be included.
Regarding export/import: The "Master password" option is only enabled if the "Save passwords" box at the bottom of the login window is checked (this has been fixed for Toad 14.1 beta, which you can get here if you want. Toad for Oracle 14.1 Beta. The 14.1 beta has had a lot of bug fixes. You will probably find it to be more stable than 14.0).