Couple things. First YQL will handle conversions to and from XML and JSON so you only need to implement a single end point for each select. So in the case of newsfeed you can remove one or the other. Secondly, when we parse JSON sometimes in order to get a reasonable conversion we need to insert a 'json' root element in the results. For your news feed case if you remove the itemPath you'll see that the root element in this case is 'json' rather than 'results'. You can change the itemPath to 'json.results' to get what you are looking for. Another option is just use the XML API from the NYT which is the one that I used in most cases.
I'd love to add your tables to the main community repository when you are finished.