With no engine or form of another form of propulsion the car would not move.
no
They allow the car to start moving after a prolonged stop with no engine running.
You can use it as long as you keep the battery charged.
Dirty air will enter the engine causing wear to all moving parts. The life of your engine will be shortened considerably.
Um... because they have an engine like your car that has moving parts and cylinders... only significantly smaller?
A good engine oil is the one recommended in your car’s owner manual. Many cars use oils like 5W-30 or 10W-40, which protect engine parts and reduce friction. Short answer: Use the oil grade recommended by the manufacturer—often 5W-30, as it works well in many temperatures and protects the engine.
Time and practice. I find you get a better feel for the clutch if you keep your heel on the floor and use it as a pivot point, and keep the radio off while practicing so that you can hear the engine. Just apply enough accelerator to get the car moving, after that shift at a decent rpm like about 2500-3000. Many vehicles now have a shift indicator light, use it while you practice.
You may use one fore home securrity. There are also types of baracades to keep your car from moving if the brakes fail.
It is important to use the correct type of oil in a car to keep the engine running properly. For this particular car, it is recommended to use a 5w-30 oil.
How about turning the ignition off at a red light? Hybrid cars will switch off the engine as soon as there is no need for it, and should you then need a "tiny" push, say to keep the car moving with the lane, the car will charge a battery going downhill, and use this when in the queue or making minor moves. But even with these you can still use a lot of petrol by accelerating with a lot of braking.
use the apropriate oils and lubes.
I believe at higher speeds there will be more air resistance.