I'm sorry. I have read your logs. They show no restrictions. And they should. IF you took the regmon logs for rundll32.exe when display properties was broken, they should have shown something. But no. However, snitfraudfix fixed something. And that's a mystery.
Plus, not being abke to register themeui.dll occasionally and havig a white list in Display Properties\desktop
That doesn't follow. A restriction dims that out. I believe you disabled Active Desktop using a vbs you downloaded. That also fixed this for a short time. But it came back.
We have gone in circles.
A repair install is not a format. Your personal files will still be there when you finish. It is a bit of work, but I can't see much hope in keeping this up.