My camera is a Nikon S6100: the flash flashes twice during red-eye reduction, and also flashes twice during forced flash. Isn’t that the way it is? Also...

Normal

There should be a weak flash when reducing red-eye.

It is normal for the forced flash to flash twice in certain modes, such as portrait mode, etc. ..No problem

There is noise from the fuselage when listening closely. It contains the sounds of motors, current, charging, etc. It's normal

The camera has sound.

As long as the noise is not very special (for example, the sound becomes louder when focusing after a collision, then it is recommended to submit it for inspection), it will be fine