The Panthers went 0-6 in their division.
Most of them prove my point.
Kurt Warner was litterally bagging groceries 6 months prior to that season.
Peyton Manning was coming off a rookie season where he completed 57% of his passes, had 28 Int's and a 71 passer rating. Yeah, everyone knew that he was going to be that much of a different QB the following season. For your sake, we'll pretend they did because only one other person on this list helps your argument, so you'll need all the help you can get.
Roethlisberger was a rookie and had the #1 defense in football. Of course, having Ward, Bettis, Staley, and Parker really made it hard on him. (sarcasm).
Jon Gruden who took a team with the best defense in the NFL and won a Super Bowl... then over the next 6 seasons compiled a 45-51 record?
Drew Brees who was just simply let go because he wasn't good enough in his 5 previous seasons to lock down the starting job?
Chad, I'm always hurt, Pennington?
Yeah, the Panthers went 0-6... and?
Andrew Luck - Yeah, he had a great year (sarcasm). He completed less than 55% of his passes and had a passer rating of 76.5. (keep in mind, Luck has a career completion pct under 60 and passer rating under 90... 2 things that Tyrod Taylor doesn't have [who's career comp % is over 62 and passer rating is over 91]... just saying). To note, I'm not saying Tyrod is great, I'm saying Andrew Luck is over rated.
Andy Reid is a great coach.
So, of the 8 factors you brought up, 6 prove my point, 2 (because I gave you 1), make yours.