If your QBs are bad it's not because you are favoring agility over confidence or visa-versa. Unless they are well under 60 those are just details. Playcalling/OL/receivers/throwing/vision/strength/VAs/SAs are far, far more important and probably in that order.
Your level 7 guys already have a negative EL. I am sorry to tell you that the problem is not how high you are taking agility or confidence and when, it is that you do not know how to efficiently build players combined with playing on bad teams. Agility and confidence should not have any SPs added until at least level 40 probably