I am not from Laminar Research; just a flight simmer from down under.
I have noticed your problem relates to the configuration of your joystick within XP10 when using the item for several types of aircraft. Amelingu is correct in the advice he has given, especially for XP10
Why not convert to XP11? Since version XP11.10 was released you can configure/calibrate your joystick for the Cessana and then save the configuration with a definate name. DON'T close the setting configuration screen
Now rearrange the configuration for the helicpter. ie where you want a particular button to perform a different operation to the cessna configuration then make the change. In particular the throttle problem currently being experienced. In the box beside the throttle allocation you can nominate the process should be reversed which allows you to use it like the Cessna instead of the method for XP10. Save the calibration with a different name and DON"T close the settings screen.
Now, if you want to use the joystick for other aircraft then repeat the process saving the config for each aircraft. Now close the settings screen when all configurations have been completed.
What you need to ensure is for each aircraft configuration you do not assign two or more buttons and or sliders to the one process and in reverse you do not assign two or more assignments to a single button or slider. If you you will have user problems. It means a careful configuration needs to be undertaken.
Now when you select a particular aircraft you also then select the joystick configuration.
You may also chose to view the following link found at https://www.youtube.com/watch?v=OEHfJA1jUBY
In the configuration process be methodical.