I’m considering learning to fly one of the helicopters available for MSFS. But I’m a little confused by having to remap the settings for my stick. Do I have to change settings I already have mapped to fly regular planes, and then change them back? Or do helos have their own settings that would be in addition to my already mapped settings for planes? Do each of the helos available take different joystick settings too?
Great Question as I also will await an answer or suggestion. Something I though about though, I think you can rename your joystick to differant names, and if this is true, does this mean we would manually load the joystick we want to use in the MSFS controls menu?
In the MSFS controller configuration you can duplicate your current joystick settings and save it under a different name. Remap buttons / axis to your other plane (or heli), and then you can easily switch between those configurations.
I have Bell 47G and I do not need to remap controls when flying it or an airplane.
Joystick does same things in helicopter as in plane.
Mapped throttle is used for collective in 47G, prop is used for throttle in 47G.
The axis controls are going to be the same. As has already been mentioned, the throttle control will act as the collective. One tip to add to realism. Reverse your throttle axis so that full forward of the throttle is full down on the collective and vice versa.
And hope that nobody ever introduces a Harrier to MSFS. Because whichever way you map the throttle, if you’ve got used to normal throttle for fixed-wing aircraft, and reversed ‘throttle’ as helicopter collective, you are going to confuse yourself when you try to hover a VTOL jet. As the numerous smoking holes I’ve created flying the DCS Harrier show. 
If there is a solution to that particular conundrum that doesn’t involve either mapping the throttle the ‘wrong way’ for a helicopter collective, or buying a separate collective controller so ‘muscle memory’ doesn’t get confused, I can’t think of one.
Correct.
At present MSFS2020 does not associate control device profiles with aircraft or aircraft type you would therefore need to manually switch between those profiles.