I got this reply by email from the author today, but I'm misunderstanding what it would take for me to echo the "Short Description" and "Homepage" values. Currently, only
echo get_feed_meta('link/name') will do anything.
The list of reserved setting names can change depending on your setup -- specifically, add-ons can add to it if they have their own feed-level settings that they use. But if you just want to get a quick look at the default list of reserved setting names (what will be treated as reserved in the absence of any add-ons to alter it), you can find that by pulling up feeds-page.php from your FWP directory and searching for the line:
var $special_settings = array ( /* Regular expression syntax is OK here */
Note that in addition to the normal special settings, there are also some open-ended reserved namespaces that are indicated by regular expressions. So, for example, not only "link/name" is reserved, but in fact anything beginning with "link/" -- this is the space in which FWP stores a number of meta-data items about the subscription for easy retrieval. Similarly, the "feed/.*" namespace is used to store the contents of feed-level elements from the last successful update. Etc.