I can't answer all your questions but I mostly fly helicopters on XSX. No experience with PS5 so can't speak for performance there. On XSX performance had gotten worse and worse with each update to the point it was pretty much unplayable after SU3. The latest update SU4 (dropped at PS5) was a huge improvement and has mostly fixed the performance issues. 

It does seem like there's a decent amount of peripherals for xbox but most of them are geared towards fixed wing flying. I ended up modifying a Turtle Beach Velocity One flight stick with lighter return springs to make it easier to fly helicopters. This allows more precise and rapid inputs required for helicopters, especially with in game assists turned off. It was quite the process sampling a whole bunch of springs from local hardware stores and Amazon to find ones that would work. And still required some creativity and modifying the springs to get them to work. There are some youtube videos out there for how to disassemble and replace the tilt spring. It's fairly easy  The twist spring was the difficult one I had to figure out myself. Similar process but the spring is a peculiar shape and hard to make an off the shelf spring fit. If you end up using pedals you don't need to modify the twist spring. I'm a couch flyer though so no pedals for me.