There is a freeze out plug behind it that seals the water jacket up. REPLACE freeze plug.
An antifreeze leak.An antifreeze leak.
Yes. Do you have a coolant leak?
Sounds like a leak in the heater core.
Antifreeze if you get an internal leak in your engine it could ruin the motor
It will leak from behind the pulley that runs the water pump. There is also a small hole in the bottom of the the pump case for that very reason. If the shaft seal goes antifreeze will weep from the hole.
A leak.
It means you have a coolant leak. It could be coming from many possibilities, some easy to repair and others not so easy. You are going to have to do some detective work to locate the source of the leak then re-post question with that info.
Probably a gasket leak. Could be the intake gaskets or the thermostat gasket.
You have a corroded core plug (sometimes called a freeze plug)
If it's coming from lower front I'd say water pump
Either a heater hose or a leak at the intake manifold
It could. On some the rubber isolator is filled with a very thick fluid.