Can't delete topic + request for decency
At times your post is deleted because the whole thread is deleted, not because your post was bad or something. And in these cases the reason for the deletion is rarely well explained (see https://forum-en.gw2archive.eu/forum/support/forum/Thread-moved-to-trashcan-forum). If you try to reply to the message about a deletion notification, someone from Support can tell you the reason for the deletion.
About the item 0, it has been tiresomely reported (see https://forum-en.gw2archive.eu/forum/support/forum/Search-feature-not-working). About item 1, well it’s really weird that a thread becomes blank instead being removed entirely, but a mod will remove it at some point.