Q: "Can't download Episodes from your feed" error - Please help

The problem lies with your media file.  The URL given for it is

http://feedproxy.google.com/~r/ConversationsFromThePorchPodcast/~5/OiJxmvFKT-Y/o pen

Firstly, without the extension on the end, e.g. .mp3, iTunes cannot recognize it as a media file. In any case, the Feedproxy URL redirects to a Google Drive URL and produces the Google player, which is in effect a web page with an embedded player. This won't work. You must provide a direct URL to the file, and the test is that when you enter the URL in Safari or another browser it plays directly in the browser, not downloads or in an embedded playey.

Reports suggests that Google Drive isn't a suitable place to host your media files; it's caused endless problems. Any straightforward webspace will do provided it handles 'byte range requests' - something you should ask about before committing to a service. Your ISP may provide webspace. Once you have found a server if you post the URL of a media file on it we can check for byte requests.