In the special tool kit, there should be a tool that attaches to a emergency crank drive "nut" on the sunroof motor to manually drive the sunroof closed if the motor fails. The owner's manual describes how to use the tool to do this.

Images available only to Customers.

If the motor is disassembled, you may have to reassemble it to get the "nut" method to work. Also, there is a possibility of a problem with the teleflex cable that extends from the motor to the roof and pushes/pulls the roof. In that case the cable might be binding inside its tube, or the cable might be broken. The repair might involve replacing the cable or the tube and cable together. Then there is the possibility of a problem with the slide tracks that allow the roof panel to slide.

To diagnose, it might be necessary to remove the headliner for access to the sliding roof components. Take a look at the factory shop manual, I am attaching a link to the free shop manual available at braingears.com:
http://mb.braingears.com/124_DISC2/Program/chassis_assemblyjobs.htm

(Your car is a Model 124 Chassis)

For the AC, there are a lot of possibilities, the first thing to verify is whether the system is fully charged with refrigerant. If so, then there are some electrical checks that need to be done to verify that the control switches, pressure switches, and other necessary inputs are available to the Klima (A/C control) relay. It is common for the control unit in the dash to fail, or for the Klima relay to fail. But to replace them without testing can become an expensive guessing game. The system is complicated, having a lot of things that can go wrong. Again, I recommend using the shop manual and wiring diagrams to diagnose.