Not sure if you know but InfoPath is End of Life with Micro$oft and not included in Office 2016 (Though still available as a download). May not be worth putting too much time into it if you plan to upgrade in the near future!
Infopath 2013 is filling the role for infopath 2016 and will be supported until 2026.
Frankly I am ending up and having the users use the XML editor. I just couldn’t get my head around getting my outputs to work with infopath, and ran out of time. Something to revisit at a later stage. It appears the documentation may relate to infopath 2003, which didn’t help me a great deal. There does not appear to be much along the line of examples with regards to that either (at least for using a ResponseRow from a DBOperation). A bit frustrating really.