I think you got some solid advises with previous posts.
Here is mine short and sweet. Becouse if i would get too specific it would take a novel long post.
1. Train the Bench powerlifting style (just a solid arch, it will protect your shoulders) if you don't want to arch before lying on the Bench roll your shoulders up and back and just lay on the Bench. Use this technique on all chest exer. It will get the delts out of the movement.
2. Like previously mentioned go for Bench rep PR's in training.
3. Reduce the number of exer. to 4 max. It would be even better to add a pullower movement for the ribcage.
4. Increasing your strength on Bench will corelate to more weight used on both Bench and on accessory exer.
Resulting in even more more mass.
5. Arnold Benched. And had the best chest in history.
So Bench.
