Correct and yet SO many people think the opposite.I agree with most of what you have had to say. However, I have never seen a thermostat that is stuck open cause a car to over heat. Thermostats play an important part in the cooling system, however, many that don't understand that have removed thermostats from their systems altogether. Also, the thermostat bypass indeed allows for some circulation, but not nearly enough to cool correctly. What it does do is help purge the system of air and coolant pockets that could lead to cooling system issues.
It won't overheat, but it will also not heat up to temp as fast as it should.