So what we see by the pic.s here is that every "flexy" part has peeling paint. The green underneath is "cast" though the part. We don't really know how long it took for that paint to start failing or if an adhesion promoter was used before application. I'm not really seeing a primer under there however that paint film looks thick enough that it was probably shot with a gun.
As far as getting the paint off I'd try this.... take each flexy part (now off the vehicle) and start flexing it and try and slide a razor blade under those existing flaking areas. I think it all might just peel off that way possibly eliminating sanding or at least minimizing it.
Next try to run down what all those flexy parts are made from. I'm guessing some type of polyethylene or other "slickish" plastic. If you need help with that go here....
https://www.polyvance.com/identify.php
Okay, so this plastic ID chart is used for repair however it is also great for seeing what plastics you are dealing with for paint work. Look down at the very bottom and you will see symbols that can help as well. Those symbols are pressed into the plastic right in mold for the part.
Well, that should be enough to get your started.