Hi Jimmy,
You can use a submit data connection to submit XML to a Web service but you will have to concatenate the string to create the XML.
Why not just use a full-fledged InfoPath XML form? The list forms are not meant for most forms. They are just for simple 10-20 field forms with no repeaters.
It's easy to do the copy and submit using our qRules common library, but that is indeed code. Good news is that you don't have to write it and you can use the library in all of your forms.
More later,