What people recommend stopping the water? Thats retarded. It has to circulate to the radiator so it can be transferred to the atmosphere by way of radiation. Yeah, slow it down some, but not stop it. The two main reasons behind restricting flow is to allow for proper heat transfer and to regulate the temp. Keep it open too long, it gets too cool, keep it closed too long, it gets hot. Its a regulator.
"The best coolant and the best pressurized system will still have a boiling point below 300 degrees. Temperatures this high will mean that a steam pocket will develop and continue to grow until the heat source is removed or a large amount of coolant is brought to the area to soak up the heat and resultant steam pocket."
I agree with this. He's not saying cooler is better. He's talking about extremely high temps causing the water to boil and steam pockets developing. New non aqueous coolants like NPG have solved this, doesnt boil until around 375 degrees. On your daily driver street car, normal operating temps wont cause this condition. If this is happening, something else is wrong and needs to be looked at. I can see and understand leaving a thermostat out of drag car due to the tremendous loads and near instant heat the engine receives, but it only receives these loads for a brief period. For a daily driver I highly discourage leaving the thermostat out. In his case, it would only mask another problem, and that is no way to solve an issue. Your daily driver isnt under the kinds of pressures and stress that a drag car is, and isnt under full load all the time. A drag car runs for seconds at a time, and thats it. Constant idling and cruising with a cold engine will wear internal parts out quick as shit. One thing he said though caught my eye. Tuned race engines running 1300 degrees? That signifies an overly rich, poor tune to me. Tuned on the ragged edge drag cars run much hotter than that. Your mom's Camry putts down the freeway at around 1450 degrees. I guess she must be running on steam only.