Keep in mind that most of the "List of Towing Laws" that you find on the internet are referencing TRAILER towing laws. Such lists are also sponsored by towed vehicle brake system manufacturers, so naturally they are going to try to tell the world that their product is required in most states BY LAW!
However, in many states the legal definition of "TRAILER" is such that a towed motor vehicle is definitely NOT a "trailer"!
However, (again), some states (and FMVSS) have braking performance standards. Here in Montana, for ANY "combination of vehicles", it is on a level clean hard surface you must be able to stop within 40 feet from 20 MPH (MCA 61-9-312). In CA, IIRC, it is 45 feet. I don't remember what the FMVSS standard is.
No, reciprocity does NOT apply. Reciprocity generally only applies to driver licensing, insurance and registration requirements.
Also keep in mind that at 60 mph you will very likely travel about 88 feet before your foot hits the brake pedal! (http://www.random-science-tools.com/physics/stopping-distance.htm) It will take you well over 100 feet to come to a stop after your foot hits the brake!
I once had a big dog run out in front of me. I hit it before I could even THINK about hitting the brake! I was driving a Ford E150 Club Wagon with 2 people in it and no cargo, nothing in tow. This was about 20 years ago, when my reflexes were pretty good. I had no chance to do ANYTHING!