I've had a Fuji XE-1 since 2013 and over 100K [estimated] shots.
The Fuji XE-1, even with its shallow mirrorless flange depth, never picked up as much dust on the sensor as my D800 cameras, which themselves never picked as much dust as my old D3 cams.
The XE-1, and apparently many other Fujifilm X cameras, has no shutter actuation count available to the consumer...I don't know if it has an internal, secret actuation count only accessible to the technicians.
As for fingers touching the sensor, my fingers seem always to be very busy holding two lenses and a body during lens changes. I have, very rarely, had visible airborne debris float into the chamber and onto the sensor during lens changes.
When the Fuji XE-1 is turned off, the shutter is open...which makes cleaning the sensor much less of a hassle than with a DSLR.
I presume most ML cams are this way.
I wonder if the shutters in the Z6 and Z7 be 'default open' as in the other ML cams?