When a file is uploaded using Digital File Pro, the file name is stored in a variable that is created under the WA Uploaded Files (file field) binding group named Server File Name.
The drawback to the Insert and Update record behaviors that are built into Dreamweaver is that they can only use dynamic data from form elements. they cannot use the server file name variable that is created. This is why you will need to use data assist for inserting and updating the record, what you are trying to accomplish cannot be done with the native Dreamweaver insert and update behaviors.
for the date, if using a timestamp column type, you can use current_time for the default value:
data-type-defaults.html