From: Pittsburgh, PA
Right now, only someone with site moderator status can remove comments. Again, this is partially why this is not a highly publicized feature. As of yet, we haven't seen any spam or anything other than positive posted.
No, there's no way to disallow at the moment.
And right now, there's no way to see (even for a moderator) who has what comments, or even any at all. Facebook's API is still rather clumsy that way.
Sorry that's not a better answer, but it is what it is right now.
Get out of the vacuum and express yourself!