I have never had an issue with editing (though I sometimes have to hit the edit button twice before it lets me).
But there is no way to delete a post, that I am aware of. Short of contacting a moderator and asking them to do it for you.
In some forums, you can delete your posts, and to delete the entire thread, you just need to be the person who started that thread and delete the first post, and POOF thread gone.