It would shorten the life span of the engine some.
They "reset" while driving at highway speeds.They "reset" while driving at highway speeds.
If by this you mean only "hot heat" when drive at highway speeds likely thermostat bad and/or almost stuck and takes long time warm up from high engine RPM during highway driving.
The distance behind the car you are following
That will depend on how fast you are driving. About 1 hr 45 minutes at highway speeds.
Highway driving tends to be consistently moving forward, whereas city driving is a lot more stop-and-go. Higher speeds are reached on the highway. Highway driving tends to be straight line and long curves, whereas city driving has a lot more turns.
Yes, it helps when driving at highway speeds.
Yes, if you had to make a sudden move at highway speeds you may lose control.
First the car engine and thus the air conditioning compressor are running faster at highway speeds, so the unit is capable of more cooling. Second highway speeds force more air over the condenser coils which are in the front of the car, which means they are more efficiently cooled by the outside air thus allowing the system to more efficiently cool the inside of your car. You might want to check the "charge" of the system if it gets really cold on the highway, and is less than adequate in the city.
At highway speeds yes, in city driving no.
2-3 rpms
Cars are rated as to how efficient they are. The government gives them two ratings; Highway mileage and City mileage. City mileage is determined by driving the car at slower speeds and stopping and starting many times. This consumes a lot of fuel during the times the car is not moving or having to accelerate. Highway mileage is determined my driving the car long distances at highway speeds, usually 55 mph or more.
Common cars can't do highway speeds (65 mph) in first gear and many have rev limiters.