Are you saying the Raptor brakes are weaker then all the other F-150's including the ones rated to tow between 11,000 - 13,000 lbs?...I was under the impression they were pretty much all the same...
In California I believe any trailer exceeding 3,000 lbs has to have it's own brakes, so having a hard time believing the Raptors reduced towing rating is because of it's brakes...
Not at all. The brakes are likely the same as the regular F-150, but I haven't confirmed that. The Raptor weighs significantly more than the regular truck, plus as you mentioned above, the rear suspension is soft(er) and long travel which upsets the stability, especially under maximum braking.
As for motor vehicle laws in Commifornia, people should refrain for citing them as an example for any other state, other than maybe New York.