Yup my CAPs never retired either, but someone said that a certain age + NFL exp. did make them retire after the first season unfortunately I can't remember what those numbers were.
Giving them 99 AWR doesn't give you any boosts in my experience. If you want specific attribute boosts you need to jack up those attributes. I know a 99 gives you a +5, but I'm not sure what the scale is from their. For those guys I would think you'd want to increase QB stats like THA or THP