What I need is to have unsubscribe requests processed automatically meaning that when a subscriber sends an unsubscribe request to the request address, they will be unsubscribed without intervention from me but with a copy of the unsubscribe confirmation sent to me.
Your rc.custom file is set correctly to do this.
Further, only subscribers must be allowed to post to the list.
Your rc.custom file is setup for this, however, if you have delinked the accept file and the dist file than this won't work, because only those in the accept file can post. For the list to accept posts from the subscribers, the subscribers must be in the accept file. This is why the accept file and the dist file, which contains the subscribers, usually are hard linked.
Do you have terminal access to your server? If so, then you can relink the accept and dist files, by running from within the list directory at the prompt: "ln dist accept". You might want to make a copy of your accept and dist files first, then remove the accept file, then hard link to dist file as per above command.
--Joyce