Not 1, not 2, but 3 sub .500 teams in the top 10. I know everyone was expecting the Cards, Panthers, and Bengals to be really good this year... but they haven't been. The Cards lost to a really good Pats team, beat a mediocre Bucs team, and got embarrassed by an embarrassing Bills team (that you have ranked in the 20s). The Panthers have a bit more of an excuse as their losses have been to mostly good teams (the Broncos and Vikings) but I am still not buying a #5 ranking for a 1-2 team who's only win came against a horrible 49ers team. Lastly you said it all about how the Bengals have performed so far this year. These are not good teams this year, shouldn't their ranking reflect that?
While your brief analysis of the Panther's Oline has a lot of truth to it, I'm not sure it's yet fair to say that their is a problem in the 2ndary. The rooks are playing pretty well and definitely aren't the problem. Another is that they can't get a pass rush because the QBs are having success throwing the ball for short, quick, Brady esque passes, but when throwing deeper, the interior rush at least is getting there, and the corners have been impressing. While they are no Norman at this point, I can say that they are one of the few bright spots so far. The main problem is that the Oline can't block, and special teams can't tackle.