No, Combat Flight Simulator 3 does not need a Flight Simulator.

There is no need to buy Microsoft Flight Simulator X: Deluxe Edition as Microsoft Flight Simulator X: Acceleration contains everything from Microsoft Flight Simulator X: Deluxe Edition and more.

No. On Flight Simulator, you fly planes, which is why it is called Flight Simulator, and has planes on the cover.

It is exactly what the name states, it is a flight simulator, it is as realistic as you can get (besides Microsoft Flight Simulator X).

No they are different