Vehicle will operate as if under heavy load.
Scientists have been working on alternative methods of energy for years. Don't worry. They will have it figuered out before the last oil well goes dry.
It might damage the engine because it might be to viscous. You need to check the manual for compatibility. Some engines allow refill with more viscous oil.
Look, figure it out! It's nun of my beeswax!
Generally you can mix the oils without a problem, check the oil manufacters label for any warnings.
the cake would be nasty and dry
A bit more information would be useful, like how many miles are on the vehicle. If it isn't a high mileage vehicle, it might be a bad oil pressure sensor.
there would be no oil and they would fail and lose money.
oil would fill the lands
Water and oil are not miscible.
everyone will die
Cooking oil is a generic term for any oil you cook with - olive oil, palm oil, soya oil, peanut oil, ... It is for cooking, not for other buisness.