Let me see if I can address some of these
Sounds are terrible. -They are pretty close actually but I hate the way Wwise sounds in this sim, frankly I think it's a big step backwards but that is my opinion.
Weather radar is wonky. (Probably due to the weather radar problem in MSFS.) I don't think it works at all, more a placeholder for aftermarket radar?
Engine controls are reversed. They are but it's no major consequence, easy fix for the Dev
Elevator feels "heavy" and animation both inside and out is limited. It's a heavy GA aircraft, twin engine on a single engine size airframe, my actual time in a 337
I recall the elevator feeling a bit heavy but that was over 30 years ago, I remember the 337 was a pain in the A$$ to service & maintain.
Windshield is tinted green. (Maybe not a complaint?) Some 337's had this, not sure why. 1970's looking tinting, ugly as hell.
Pilot's seat position is too low, and cannot be adjusted in the config file. It's going to vary from one pilot to another, the real 337's seats are not height adjustable, get a pillow! LOL!
Brake animation is wonky. ? The braking effect on most models are, again it is an FS2020 quirk, maybe too exaggerated?
Ground handling is too sensitive. Yes, like most aircraft models in FS2020, it is an FS2020 issue but you can dial it back in the menu before flight
Flickering lighting in the cockpit. Yes
Flashes of daylight under the door frame. Yes