1) The inoperable sunroof may be due to a dirty switch at your console. You can apply some voltage directly to the motor to make sure...if it works at the motor, you likely have a bad switch.
2)This happens a lot. They become dry and brittle. Do not settle for bargain-rate return lines; get them from the dealer.
3)N/A
4)It may or may not be your engine shocks. Shaking at idle has proven to be a real bugaboo with these cars. It might be your engine and/or tranny mount(s).
5)The tranny shift can be adjusted via the modulator, and it's a good idea to go ahead and change the fluid and filter (a messy job). The rumble in the back may be caused by a bad tire, a worn driveshaft mount, worn axle shafts...or any combination thereof.
6)Vacuum leaks are common in these cars. Look at the door lock regulators/plungers first. They become fatigued and fail long before the lines themselves are suspect.

__________________
Matt
------
1995 E300 Diesel (Die Blau Frau)