Hi there,
1- Bummer!
2- Not sure.
3- The instrument cluster can be hard to pull out when it's been in place for years. Keep working at it with bigger pull hooks, I use cut-up wire coat hangers. Eventually it will wiggle free. Try to get a used LCD display, new ones are expensive - $300 I think?
4- The sunroof is not really a DIY repair. Many horror stories abound, usually ending with the car at the dealership (who have special tools for it), and a repair bill over $1k.
5- The black lines are vent lines to the passenger compartment. They're not supposed to connect to anything. There are a lot of vacuum lines in the tranny circuit, make sure you check ALL of them, including the rubber fittings under the BFS (Blue Flying Saucer). Last two items would be the modulator on the tranny, and the signal generator on the side of the injection pump. If the trans fluid & filter has not been changed in the past 30kmi, it's overdue (don't forget to drain the converter too). Schematics are in the factory service manuals, and please don't tell me you're attempting to work on this car without them!
6- FastLane, who sponsor this forum, can get whatever you need. Alternately call Rusty (800-741-5252) at ***************. For a list of vacuum lines and fittings, read this:
http://engine.mbzarticles.org/diesel/hoses/
7- Leave the emissions crap disabled!!! Please!!! See photos:
http://www.meimann.com/images/mercedes/W124_stuff/smog_lines_plugged.jpg
http://www.meimann.com/images/mercedes/W124_stuff/smog_solenoids.jpg
And for lots of photos of my 1987 300D's, upgrade & repair projects, etc go here:
http://www.meimann.com/images/mercedes/