[@La Inquisidora]
Deleting PMs is actually a more complex system than one would think. They are essentially forum threads with restricted access. When deleting a PM, what you would really be doing is remove yourself from the access list to said thread. Only after all people who once had access to said thread has "deleted" it, would they truly be open for deletion. What [@Mahz] is planning there is to have the system check every now and then for conversations like that (once the access removal system is coded in, of course). We're fairly sure this will also be coded when he codes the stuff for adding people to a pre-existing PM thread.

[@Mahz] Discovered something that might need fixing on the @mention buttons. No matter where you are in a prospective post, pressing the button will put the @mention text at the end of the post. Putting it where the text marker is instead would make said button even better.