No offense, but it is obvious you are not an engineer.Let's work this problem through a thought experiment. I'll present two scenarios and how it affects the engine, transmission, brakes, suspension, and structure of the vehicle.
Scenario 1: Putting 200lbs of weight in the trunk of the car (normal operations)
Scenario 2: Putting 200lbs of weight in on the hitch that is structurally connected to the frame of the car.
Scenario 1 is the no-brainer "very safe" scenario and scenario 2 is the one in questions. Now let's look at the difference between the two and we can conclude how scenario 2 affects the car.
Engine: Putting 200lb load on the car, regardless of where the load is placed (in the trunk, on the hitch, in the passenger seats) will require the engine to work just as hard to accelerate that mass forward.
Transmission: Transmitting power from the engine to the axle. The transmission would again have to work just as hard to regardless of where the load is placed.
Brakes: Convert kinetic energy into potential (battery) or heat (brake pads) will have to convert the same amount of extra energy from the extra 200lb regardless of where the load is placed.
Suspension: This is dependent on where the center of gravity of the vehicle is. 200lb in the trunk vs. 200lb on the hitch will have a slight difference in the center of gravity and ultimately how much load each suspension will have to carry. However, i don't believe this is would cause the rear suspension to wear immaturely.
Structure: There is a difference in terms of structures based on where the load is placed. Placing 200lbs on a hitch will cause a moment about where the hitch is mechanically fastened to the frame of the car whereas putting 200lbs in the trunk will not. However, I believe there is enough design margin of the frame of the car to absorb this. Think about it this way, if the frame of your car can withstand hitting a pothole going 65mph (maybe some rim damage), it should be able to withstand the load caused by the hitch.