There are basically 2 causes. One cause is condensation which is normal. This is the hot exhaust hitting the cold parts causing water to accumulate. It goes away after the system warms up. The other cause is a blown head gasket which is very serious. If the water smells and taste sweet, it is coolant and you have a blown head gasket. Stop driving the car immediately and have it repaired. Other signs of a blown head gasket are coolant in the oil, air bubbles coming from the radiator inlet with the cap off.
You have a problem with your engine.
ac or exhuast
Running rich- either due to computer or faulty fuel injectors or carb. adjustment
yes it can kill you
Not normally.
No!
on the exhuast header pipes
Weld the place where it is leaking
no you cant
if your car is getting hot its usually the first clue... if its smoking (coolant out of the exhuast) or is making exsesive pressure in the coolant system its from a bad head gasket letting water in the cylinders and then exiting out the exhuast or vicversa pushing air from the cylinders in the coolant system... either way if its doing that it most deffinatley the head gasket
in the exhuast system one before the cat and one after the cat
Any that is not stainless steel