Yes you need to include it.
Yes you import it back in as External ID.
Review the documentation at https://www.odoo.com/documentation/18.0/applications/essentials/export_import_data.html#update-data-in-odoo
0
Yes you need to include it.
Yes you import it back in as External ID.
Review the documentation at https://www.odoo.com/documentation/18.0/applications/essentials/export_import_data.html#update-data-in-odoo