The air ducts are good, I will check them again when I have the wheels off to flush the fluid again.
All the pads are wearing well, I don't think there are sticking calipers. My 944's rears were acting up, but those are sliding calipers.
The R4s is like the hawk HP+. They are aggressive street pads. I didn't expect them to be perfect, but was surprised how fast they went away.
I ordered a set of Hawk HT-10s for the front. They work from 300-1600 degrees. The rotors would be glowing bright red before the pads give up.
I was/am running street tires, but that was part of the problem. I had to slow down a lot because I couldn't go around the corner as fast as if I had race tires. Therefore relying more on my brakes.
I will report on how the setup works at Fontana.