It won't hurt the engine but it will hurt the catalytic converter.
Absolutely!
No it does not affect
No, it will not hurt you.
if you mix the ratio right with the gas it will boost power to engine as far as hurting engine i cant see why it would hurt it .
No it won't hurt the engine BUT you could get carbon monoxide in the car. Don't sit in a parked car with the engine running if your exhaust is bad - it could kill you.
Repeated attempts to start a car will not hurt a car as long as the engine has the oil it's supposed to have. However, they aren't good for the battery.
Lots of it will.
it adds a lot of strain on the engine especially if the drive train is directly under the engine. (front engine fwd, or mid engine rwd)
no
Yes. Can clog coolant passages in your engine and other areas.
A man in new jersey tested this out and was disappointed to find out the engine stalls and does nothing. Also it will not hurt the engine.