It won't hurt the engine but it will hurt the catalytic converter.
It does not hurt an engine to run it with no exhaust muffler
as long as you have not driven the car very long with the water pump bad and overheated the engine, it is fixable. the engine is a noninterference engine so it is not going to hurt the engine if the belt breaks.
Not sure what a small amount of water is, a drop? A couple ounces? A pint? Anything more than a couple drops in the crankcase wouldn't be healthy for the engine.
A full cup of water or less can hurt any car's engine. While some very small amounts of water may find its way into fuel tanks naturally, any more water than this will cause a car serious problems. Should water get into a fuel tank, it is important to get it out again so the car's engine will operate properly. There will be no permanent engine damage. The engine will simply not run.
Toy water guns with water in them only hurt if they hit you in the eye.
The Villager does not have an interference engine.
No
Absolutely!
if the engine is not designed to run turbos it can do a lot of damage. a turbo engine has hardened internals
Yes it can hurt your engine to drive with a bad knock sensor. The knock sensor should be replaced as soon as possible.
Yes, a head gasket can blow and cause the engine to overheat. Happens all the time. Yes spaying cold water on an engine that is at full operating temperature can possibly do some damage. Not likely, but possible. Spraying water on a warm or cold engine will do not damage to the engine. It may however damage parts such as the alternator, or some sensors. Never use a high pressure spray.