I have had salespeople (thankfully not in Austin) tell me virtually the same thing, and that weight ratings were for paranoid legal eagles who just wanted to make people buy heavier duty vehicles than they need...
The ironic thing is that insurance companies know (or can easily find out) the vehicle weight limits of the vehicle insured under them via the VIN and other details. They know the weight of the trailer via model type and VIN. A wreck with a grossly overloaded trailer, they will just deny claims, call it negligence, and walk off.