Just to update the thread -- The failed to select node for list id error resolved itself -- not sure what was happening there -- maybe an extra space snuck into the command someplace?
Then the mapping had a URL that included a view -- we want that to just be the base SharePoint Site URL. The submit data connection needed a modification so that the listName parameter was including just the text and child elements....Finally (and here is where we knew we had this thing at our mercy) there was a SharePoint List column with a data type that was not the same as what we were submitting (it was yes / no and the data was not).
All's well that ends well, and the form is submitting to the list now.