The only reason you would need to know who deleted something is to pester them about it, which would be a pointless annoyance that might even prevent moderators from doing a good job. Admins are the only ones who can restore deleted posts and the only ones who can properly deal with inaccurate mod actions: post in Meta and we'll look into it.
Self-moderation is moderation
in addition to global moderation. Both of those posts were insubstantial, so deleting them seems correct.
I guess whenever your post gets deleted because of the comment to which you responded to also got deleted, you personally get a message from the moderators explaining that "the post got deleted because it was a reply to other deleted post", at least this is what I got from grue when my post got deleted in these situations. So I don't think this is the case.
That sort of message isn't always sent.
I wouldn't call it anonymous either. Most people who frequent the ALTCOIN sections knows that mprep is the moderator.
Even sections with assigned mods can also be moderated by global mods.