in the manual it's stated one can change the sensivity of the mixture control by using the right friction lock. But is that only for hardware bindings or does even change the sensitivy when I use the mouse?

It only changes the sensitivity when using the mouse wheel on the mixture control. Sensitivity of your hardware controls is dependent on your actual physical hardware controls or the binding/sensitivity curves that you've assigned to it.

@Zacke said in two more questions: sensivity of the mixture/flap bindings:

And I can't bind the flaps to my joystick buttons. I tried the different flap commands (continous etc.) but nothing's happening within the Commander.

The ordinary Increase/Decrease Flaps bindings in MSFS should work just fine.

Don't use the Continuous ones unless you know what you're doing. If you want the continuous flap control to work, you'll probably need to use third party binding software. There's an example of how to do that with Mobiflight: https://community.justflight.com/topic/11197/axis-control-for-cowl-flaps/26?_=1789410025015