The OP title noted that the towing laws are totally confused. It would help if there were a common set of laws across the USA. But this is an issue left for states to decide and enforce above the federal laws.
So it is left to the individual RVer to keep himself up to date on the requirements.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot