I think it would be so much better if players didn't always trend down in ratings in year 9. It's realistic that players start losing speed and physical traits as they get older but i think it should be a little more random. Maybe a guy might start slowing down in year 7 or 8 or if he's a freak he may still be fast into his 10th or 11th years. I just think it is too robotic to have players (mostly skilled positions) to hit the wall in the exact same year.

I would apply the same random weighting to the retirement percentages as well. I know every DL is safe until their 12th season now. That could mix it up too.

This. Although I would rather player development be actually tied to coaches and player ratings +/- not be linear.