Airspeed and Throttle in different flight modes

ArduPlane Plane 3.7
1

Hi!
I have a few questions regarding how the throttle and airspeed is handled in the different flight modes.
Important info: I am using a airspeed sensor.

  1. I see that in FBWB, the throttle stick on the radio is actually controlling the throttle between ARSPD_FBW_MIN and ARSPD_FBW_MAX. The throttle output from FC to ESC is limited by THR_MAX.
    Correct?

  2. THR_MAX is by default at 75%, by increasing it to 100% the plane becomes more capable of handling headwind, what is the negative consequence of increasing it?

  3. How is throttle and airspeed handled in CRUICE? Same as FBWB with the additional adjustments based on changes in desired altitude by the elevator stick?

  4. What is the target airspeed in AUTO? Is it TRIM_ARSPD_CM? If throttle stick is kept at 50% the target airspeed is set to TRIM_ARSPD_CM?

  5. Is throttle nudge accumulative, such as altitude adjustments in copter, or is the range between 50% and 100% defined as the range from TRIM_ARSPD_CM to ARSPD_FBW_MAX (and similarly 0% to 50% throttle corresponds to the range from ARSPD_FBW_MIN to TRIM_ARSPD_CM)?

  6. Does RTL use TRIM_ARSPD_CM as target airspeed?

  7. What about LOITER, CIRCLE and GUIDED?

  8. What is TRIM_THROTTLE?

Thanks a lot for all answers.

2

I have found another parameter I need clarification on:

When is MIN_GNDSPD_CM used?

The parameter list says it is used “when under airspeed control”, does that mean FBWB, CRUISE, LOITER, CIRCLE, AUTO and RTL?

P.S.: I know that these are quite basic questions, and I am therefore hoping they have basic answers.
I have looked at the documentation and the parameter list, but I am still not sure how the parameters influence the plane in the different modes. I also want to add that I think the plane documentation is lacking compared to the copter documentation, e.g. the documentation on AUTO mode doesn’t mention velocity or throttle at all.