The reason that we do not allow members to delete their threads is because to do so would disrupt the continuity of the forum. This would also give you (the thread starter) the ability to delete the posts of everyone who had replied to the thread which in turn would disrupt and decrease their post count. We (the staff and admin) do not delete threads for the same reason.
If you have started a thread that has no replies, send us a post report asking to have it deleted and we will take care of it.
If you notice a typo or something else that you would like changed, again use the report post button and let us know. We will fix it for you.
Something else to take into consideration is that if you got the answer that you were looking for it is quite possible that the thread will be helpful to the next person seeking an answer.