When I edit a post before sending it I usually jump between the words of my post by using the ctrl+cursor keys.
If you are a codegarch and don't already do it you should try it. It is a very convenient way to move the cursor precisely through lots of text without having to use the mouse.
If I then decide to delete ans word I usually jump with the cursor in front of that word and then press Ctrl+delete.
In every common text editor this will cause the whole word to be deleted. This also works with a post but I also get this retarded messagebox if I want to delete the whole post.
This is a very annoying behavior. I doubt that anybody needs a keyboard shortcut to delete a post that hasn't been sent yet that you then additionally have to confirm with a messagebox.