Why can't I post anywhere else?

[Shougun]

You can delete posts by selecting edit, clicking delete, following the form as desired (giving a reason if you want), and finally clicking delete post instead of the save button (Varies slightly if you go the advanced edit button or in post version).

However, you can't delete your own thread :P.
At least when I made a duplicate thread on accident and wanted to delete it, I couldn't. That was a long time ago though, you should try