Hi @map @nhk.
Commenting, inappropriate content flagging, and deleting of comments are all being released this and next week. Right now you can delete your own posts, but you'll also be able to flag anyone that is inappropriate and also delete any comments on your own posts.
We're also going to allow each user to decide whether or not to allow commenting on their posts at all. We will block trolls and inappropriate users.
(@anna at Ello!)