Assuming we are talking automatic transmissions, you would use park or neutral to start the engine but neither one are gears.
With a little practice you can start a vehicle in 1st gear and shift gears without the use of a clutch. This would be only to get you safely home or to a garage.
Where you find gears on the island, you will normally use the Multi-Tool which you get from the Cantina at the start of the island. To turn the gears at the cantina, use the crank at bottom right. To start the elevators in the annex (with the Mech), just exit the Mech to turn them on.
Different costs, it depends what airline you use. If you use a car, it depends on what fuel you use.
Shifter or Shift Knob
The gears are always being used in an automatic car, if you are asking about the 1 and the 2 on the shifter, i dont know what those are for, you can use them to slow down if your brakes go out.
Overdrive just lets the car use the lowest gear. Without overdrive you are probably only using 3 gears, and with it you are probably using 4.
No, the throw out bearing in a clutch is needed to keep an disengaged clutch spinning. you can drive a car with a bad throwout bearing if you don't use the clutch By "floating the gears". You must disconnect or bypass the start safety switch (this is when you need to have the clutch pedal to the floor to start the moter) so that you can start the car in gear if you come to a complete stop.
Manual transmission is when you use the shift stick to shift to different gears in a car instead of driving without shifting gears,which is auto transmission.
No, but not all engines use a timing chain, some have belts and some use gears.
The starter is what helps for only you to be able you use your car. Usually the starter is calibrated only to work with your key, and will send electrical signals that cause your car to start.
D.C. current is the only current used in your car. If you jump a battery from another battery, that's D.C.
Yes, the only thing the key will not unlock is the glovecumprtment and it will not allow you to lock the car without the remote control.