In Vantage, the custom form builder will allow you to add the fields you describe, but currently the main search does not search these custom fields. If you have coding knowledge then yes you can potentially modify the theme in order to make those fields searchable (there is no encryption which will prevent you doing this). Whether or not you "break" the theme in the process depends on whether or not you know what you're doing though ;) As a comparison, our
ClassiPress theme also has custom forms and fields functionality, and the advanced search built into the theme already does allow you to search by those custom fields. Thanks.