Yes. You can crimp too much where you start deforming the bullet shank (the cylindrical portion of the bullet).
Crimps should be as uniform as possible, and most revolver bullets have crimping grooves on them. For heavy recoiling loads such as 454Casull, you definitely want a firm crimp since bullets could move under heavy recoil.
As to accuracy, some guy with a rifle was experimenting with pulled bullets, either pulled with pliers, so that there were marks on the bullet ogive (the sloping/tapering portion of the bullet), and there wasn't a large degradation in bullet accuracy with that compared to deformations in the bullet base (the bottom of the bullet where the hot gasses hit). The experimenter also did some intentional damage to the bullet, such as filing one side of the bullet base.
Essentially, you want a concentric bullet, so that when it is spun by the rifling, its not out of balance