Wow... You have asked exactly the same question what I thought of asking...
Mine is a larger group with a size of around 900 members. Think of the pain in doing this process for all those invites which are sent but 100s of users request to subscribe via online... Definitely, the best way to handle would be to automatically approve the request...
Contrarily, if the user requests via a new email id and wants to remove the invite sent to old email id, I go to the send invitations page which loads around 20 invites per page and then I have to scroll 10 to 15 times in order to find and remove the invites that are already sent. There should be a search option here to select the invite.
Balaji
