So far everything seems ok. Personally, I see no reason to delete a person from a memberlist if they have 0 posts, or to delete their accounts because they’ve become inactive.
I’ve been a member of many sites where I’ve forgotten my sign in name and i check the memberlist to see what it was.
Its hard to get all members to be active, many lurk and read, especially if they’re not really familiar with the subject, we shouldn’t punish them. They’ve signed up, there’s a chance they may start posting.
Witchy, to unsubscribe to the site / forum posts go into your user cp, go to List Subscriptions and remove the ones you no longer want to be updated on.