On your update page you need to bind the form fields to the values from the recordset to maintain the existing values. When it comes to the images you will need to set the default image in each of your upload server behaviors to the value in your recordset that holds the existing file name.
As for inserting and updating records if you add 4 values initially you will need to update that existing record and not insert a new one. The update page should only ever update records, if there is no insert on this page then it will not insert new records. I only saw the update server behavior on your update page.