My podcast list is complete in iTunes preview, but does not appear in iTunes when I subscribe.

You have introduced a fatal error into your feed. The 'link' and 'enclosure' tags within the episode for 7 June contain the URL

http://stanselms.org/podcastgen2.2/?name=2015-06-07_32_body_&_blood.mp3

You cannot have an ampersand ('&') by itself in an XMP feed because it signifies the beginning of a code sequence which is never completed. This renders the rest of the feed unreadable because it looks as if it's part of this non-existent code. As it invalidates the closing tags that renders the opening tags invalid and so the entire feed becomes unreadable which is why it turns up empty when subscribing.

The Store is showing the feed, which it caches, as of the last time it could read it. Oddly enough the episode in question is there, so either you've made a change to the URL since July 19th or the Store is ignoring the error - though the iTunes application is plainly thrown by it.

You will need to rename the file concerned to remove the ampersand and amend the feed accordingly. The 'link' tag should contain the URL of your website, not your episode, but in any case is not read within episodes, onlly in the top section of the feed, so you can remove the URL entirely. You should probably check the feed for any more stray ampersands, then having corrected it re-upload it and subscribe to it to see if it now works.

Any time you need to have an ampersand in text you should replace it with the code

&

however you should never have one in a URL as it can cause problems quite apart from the XML issue.