well it's not necessary to delete your whole account,just mark your posts or threads for deletion and if the mods agree to deleting them then they will be deleted,though try to do so in as few reports/requests as possible,as you can imagine they get tons of complaints or reports or requests for some form of deletion simply take "appropriate" steps for deletion of your posts/threads and leave it to mods,no need to worry,besides half of all you post whether a thread or post,goes to the back eventually,so try not to stress so much!