We discovered that our Wordpress refused to send emails out with the result that people who registered didn’t get an email with the password. And this way we also got no info regarding comments in order for us to air them. (A big thanks to Ralf for this info).
However, we changed that and by now you should be able to write comments without having to register. Comments will still be checked manually and then aired.
So if you want to put in your two cents – go ahead!