A very nice plugin, thanks!
Could it be tweaked so that posts from staff members were not shown in the list? We only care about ordinary, poor users who did not get a reply. Staff members somehow will deal with that, I hope. 
Ideally, it would be awesome to have one more filter, that showed posts that were not replied to by the staff. Just in case we to make sure a post was reviewed and answered by at least one staff member and not an ordinary fella.