Your car is still making over 300rwhp at 5800 rpm there is no reason to shift your car before that. Your graph is fine and for a lid only car 312rwhp is normal. Have Brian set your shift points to 6000 rpm and I would talk to him about making the car alittle leaner. 12.5s is way safe. I would want to see your car in the 12.8-13.1 range.
There is nothing wrong with your car and you need to use NGK TR5s with your setup they should be pregapped for you but make sure you check them.