Excellent, a Biopsy on the harness pre-surgery. Now you have a worthy shot. The overview was helpful. I indeed thought you were on the E320.
Pulling that baby doesn't look too bad. Splitting the molded connector to re-wire looks like the only challenge. The actuator pics (thanks raul) show a grungy throttle butterfly plate. Look down the intake with a flashlight, my plate looked similar with brown crust on the edge as well gunk in the throttle body bore. I'm not a fan of carb cleaner as a first choice for this but I'm sure it would work. I poured a couple ounces of SeaFoam (Google if you don't know the product) in a spray bottle and with clean rags wiped it out after a few squirts to soften things. Cleaned up well. I was careful not to press or try lifting the plate, its hooked to a motor gear drive. I sprayed a couple shots of carb cleaner on the plate pivots to clear any hiding goo.
The old MAF created a surge or RPM drift - 13,000 two seconds, drop to 900 for two seconds, back up to 12K - on and on. After a replacement MAF it held 700-900 much better but varied. I replaced the dash temp gauge sender as drifting but I'm fairly certain it's not related to idle. The throttle cleaning did it, 700 always.
The window, radio and other phantoms are probably not related. Have you swapped or have an OVP relay? It is reported to be the very one when multiple ghosts appear. Sorry the harness job was unrewarding, that had to be fun. The actuator has idle and cruise duties and hopefully is where the evil lives. Getting the code tool operating may be a bonus but if the storage registers are locked up you may not get any output. I'd consider taking it to Mr. Dealer and directing them to pull the codes (tee-hee). If they can great, post the codes and go fix your tool. If they can't, pay a minimum fee for the attempt. Codes reveal great info. fighting these things.
Good luck with the rewire.