Black
Black smoke indicates a rich fuel mixture.
Engine is running lean.
It's a turbine mounted in the exhaust manifold to give more power and smoother running to the engine.
No, not really. An engine will run without an exhaust (but you may get arrested). The exhaust simply directs waste gasses and quietens the noise. It plays no part in the running of the engine, but can reduce the performance if it causes on obstruction to the gasses.
Moisture in the exhaust, or a cold running engine.
Sounds like exhaust leak.
T he rest of their life.....
Its a long shot but... If you have a leak in the exhaust before the oxygen sensors, the sensors will think the engine is running lean. The computer will compensate (from incorrect input data) by increasing fuel delivery, causing the air/fuel mixture to go rich. If the engine runs super rich the exhaust will be black, and very noticable when you accelerate.
They are 500-1000 degrees F, depending on the engine.
if a small amount of water is dripping it is normal condensation from running an engine
Exhaust fumes may enter and that is not good.
Not if the engine is running. The turbo is powered by exhaust gasses.