At least I can help you with the white screens on the CJ4. Had exactly the same issue…
In your community folder you have a mod or a livery that is causing this error. In my case it was the “working-title-cj4” mod that was causing the white screens. But maybe not in your case. Doesn’t hurt to try.
Move all your cj4 liveries and mods outside the community folder and restart the game. You might also try to deinstall the cj4 aircraft inside the content manager and reinstalling it. This way you are sure the cfg files are reset.