I don't think I'm overlooking anything with deleting a message :c If I am, I'm so sorry! I received a PM this evening, read it, and still had the notification icon afterwards. There is no "mark as read" or "delete" button on the page and I can't for the life of me figure that out.

edit: the icon is very suddenly gone xD It did take a good ten minutes to register that I had read it however.