1) Ability to restore own thread
There is a permissions for deleting own thread, but figures that once it has been deleted (soft-deleted), the author cannot see it anymore, and he cannot restore it should he need to. Only option is republishing or getting a moderator to restore the thread.
2) Ability to lock/unlock own thread
I did a small hack for closing threads older than 30 days, to prevent people digging old threads and spammers adding messages. However, I liked the fact that I could give the original author the privilege of unlocking their thread should they needed to revive them for contributions. That was really useful. As it stands now, that is not possible.