I think the safest way would be like piratebay, no registration necessary, no logs just a plain website to upload .torrent/magnet link with description and place for comments.
indeed, but torrents die so fast it's not even funny
a private (or semi-private) tracker would be better
i don't think security would be a big problem if things would be done correctly (there are still soooo many safe countries where to host)
AND we shouldn't forget that we're still dealing with japanese porn, not hollywood movies, MP3 or warez: after the whole cyberlocker business have fallen, i'm expecting the death of 99% all the jav blogs floating around; that will mean A LOT less exposure, and a bit more "safety" (not exactly, but you got the point)
maybe these are just stupid thoughts, but i don't know... it's an idea i always had in my mind but i never had the balls -nor the skills- to work on
EDIT @elgringo: actually it was, but people weren't interested enough to report about it