There is no advantage to running a cooler thermostat. Heat = power. To get the best performance you want to run hot without causing cavitation. If you have to run a cooler thermostat then your cooling system is not functioning up to par. Most of the time it is due to sediment plugging the radiator tubes.
The Silica based coolants are engines call for breaks down over time. Typically two years is all it is good for. It should be flushed and replaced with new coolant and distilled water. Water pump failures are caused by contaminants eating away at the impeller bushings. Those contaminants usually come from using plain old tap water.
If you run under extreme conditions you should consider going with a
Flowkooler water pump and an oversized radiator. I also run
Evans Coolant in my track car and motorcycle. Evens is a waterless coolant that does not boil. I run a 220 degree thermostat in the track car and never overheats or knocks.
Another issue that can cause heat problems is thermostat flow. Many cheap ones don't allow much flow and the engine will run hotter without getting the water through the radiator. You can do a search on summit or jeggs to find some good ones. They only cost a couple of bucks more than the cheap ones.
One of those infrared thermometers is a good tool for checking the radiator. I've seen some so plugged that the lower half stays at ambient temp.