Doing what BK advises will check out the performance of all of the "over temp shutdown system" EXCEPT the actual sensing unit. I would have them out and in a pan of water on the stove with a thermometer in the mix.
I have been told that over the years and for different reasons these type devices get disconnected.. Instead of repaired at some point, I guess. They are all suspect for that reason.
I would check the operation of the low oil sensor during the drain step when I changed oil. Every time I changed oil.
I would opt for an "overfull oil sensor" for the oil as well. Collent leaks and fuel leaks into the sump will ruin the engine long before you detect the missing coolant or note the reduced MPG(
I think a low coolant alarm is appropriate, also.
Not all these sensors need to shut down the engine but a buzzer and red light on the dash is a minimum alert. I have these added to my motor home.