Well I think I got the #3 question sorted out. It looks like everything I had left all pretty much hooked together. Below is a photo of what it all looks like plugged together.
I still have two connections with unknown mates. One is a single wire connector, and the other one comes off the steering column. I'm guessing this one is part of the airbag system, but not sure where it belongs either.
I took a chance and tried hooking a battery up to see if magic smoke appeared anywhere. So far so good there, but I'm getting a couple really weird things happening. First is that the battery light is on all the time. Doesn't matter if there's a key in the ignition or not. The second issue is that there is a hum or buzz coming from the intake area of the engine. Again this is when nothing should be on at all since there isn't a key in the ignition.
I had my wife try to start the car for the heck of it, but there wasn't anything. Not even a click from the starter. All the relays and fuses are in place. No fuses blew in the process, so I guess that's good.
Any thoughts on what might be up other than something isn't hooked up right?
Stu Ritter from the Mercedes list turned me on to another site that he said should have the schematics for the entire car at
www.startekinfo.com. Unlike the Mercedes parts site you have to pay to access it by the day, week, month, or year. Pricey at $18 just for one day, but I'm going to give that a try next.
-Dean