I think guest should be able to vote only on the post, not our comments nor make comments. If they don't have the BALLS to "come out", they should stay out. Nice guests are few and far between; the nice ones should make a username so they don't get lumped in with the dickhead-troll-guests.
Like a week ago, I told my Mormon friends that the Thorki shippers probably flipped out at the part where Loki turns Thor into Sif and tells him he looks ravishing. They aren't really into fandoms so I had to explain what shipping was and when they understood they just stared at me like 'w..w..why?'. Then one of them said "But they're both boys..." and I just stared at her like 'is there something wrong with that'. We haven't talked about it since.
Guest posting really aught to be turned off for a while.