Regarding your sunroof not moving back - try lubing the tracks.
Mercedes sells a specific grease to be used for this. If you can't get any, I'd try any all-purpose grease, or even WD-40, and see if it works.
My sunroof stopped moving once, and I took it to a local Mercedes shop. They noticed the tracks were bone dry, added some grease, and it is back in action.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".