Hi Polonus,
I do concern about copyright material, giving the exact citation or backlink to the resource, or asking to reproduce should be a wise way to avoid infringement. I use Digiprove for my wordpress blog, but still I put creative commons noncommercial share alike for my works - since I have no intention to gain any material profit from it.
[Digiprove is here:
http://wordpress.org/extend/plugins/digiproveblog/]
I use a strict blacklist setting for comment form with WP-SpamFree (instead of Akismet), so I do some customizes and protect my blog again spams. And a strict moderation setting especially for those who give external link(s).
I don't know if this enough, but I think it safe for now.
Thanks for you links, shall give a check soon
Cahya.