No, the check engine light will come on at first, and in the long run the oil will sludge up form running to cold.
Running it while leaking can cause it to overheat repeatedly, which can cause thermostat damage , along with other problems.
If the thermostat is stuck in the CLOSED position, the vehicle will overheat and may cause a lot of damage. If it is stuck in the OPEN positin, the vehicle may not reach normal operating temperature and the heater may only blow warm or cold air.
A bad thermostat can cause an overheat. A bad temp sensor can show an overheat when the temperature is normal.
Yes, a thermostat opens and closes in response to the temperature in the cooling system under normal conditions. If it is sticking it can cause fluctuations in the radiator coolant temperature.
Bad thermostat
I would suspect the thermostat is stuck open. Replace the thermostat.
If you are allergic, possibly. If you are normal, then no, it will not cause hives nor do you any damage. You could however damage the fish badly by touching it.
Running a vehicle without a thermostat will cause it to take longer to warm up and your interior heater may not blow hot air.
Best way to tell your normal operating temperature is to visit an auto parts store and ask them what the OEM thermostat temperature is (or you can look it up yourself on Autozone.com). Most cars these days will have around a 190 degree thermostat. Your car will run slightly hotter than that temperature as it is needed to maintain the thermostat in an open position. With that thermostat you can expect to see the temperature of the water stay around 205-210. If the water temperature ever starts to get above 240 you should shut the engine down to avoid damage and have the cooling system checked. Temperatures above 260 WILL cause significant engine damage.
Code 17 is engine cold too long. The normal cause is a failed thermostat.
If you are unsure if it is heating because of a water pump or a thermstat, you can find out by removing the thermostat. If it still heats without a thermostat, then you know it is the water pump. Without a thermostat, the water flow has nothing to cause it to heat unless the water pump fails to circulate the water. No circulation of the water would cause the over heating.
Reverse / thrust faults at convergent boundaries typically cause the largest Earthquakes and so have the potential to cause the greatest amount of damage.