I have resolved the RC problems. It was a defect receiver in fact, and after changing to a new one, the binding process worked fine, as well as the radio controls calibration.
Now the next step : calibrating and arming the ESC's. I think the calibrating worked, as I heard a lot of different bleeps and melodies, but as I bring the throttle back down after a few minutes, I have no response of the motors to the throttle. Also after unplugging the lipo and repowering, I tried to arm (throttle to the right bottom for 3 seconds ...) but no response .....
What's wrong now ?
I had the switch in fly mode, I suppose that's OK ? The blue LED on the board is blinking slowly.