[ArneBab]

Yes to the first.

To the second no: In Freenet 0.5 there was a plugin for that, but for 0.7 this has not been written yet.

You can write that, but you cannot check what exactly it would block. Whom do you trust to censor you? The devs cannot make that judgement. And who will control the censors? You would need a list of all chunks to block (by their routing key).