When Pop email is talked about as a premium member benefit, is it just talking about the ability to access pop email accounts that are external to chess.com through the chess.com mail interface, or does it mean you can access your chess.com email account through pop? If the latter, are there instructions somewhere? I haven't been able to find any.

Hiya, here ye go, from the help box with a search of "email" ;P

http://support.chess.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=181