Stuck thermostat, low of coolant, defective water pump, cooling fan not working, radiator exterior clogged with debris, and lastly a blown head gasket or cracked head.
no but if you try to run the car with the water pump out you could overheat your engine
a restriction somewhere in the cooling system maybe the fan
No.
Yes, it could even make it completely ineffective. If it is in a car it can ruin gaskets, seals, or make your car overheat. Which can warp your the pistons in you car.
Yes it could
drive it without coolant
yes
Try changing the themometer
Yes
There could be many reasons. Not enough coolant or bad flow, faulty thermostat, low oil. If the coolant freezes then it will overheat. If your car continues to overheat then you should have the coolant flushed and thermostat replaced.
No, not an alternator itself. A slipping belt driving the alternator and the water pump could though.
Not likely but possible.