#1: Dunno, mine hesitates on start-up except the first time everyday, and thats it. It used to stutter at lights but stopped, cant help you there. Sorry. But someone can, that ? comes up a lot.
#2: Door panels easy, open it and you'll see what needs unscrewing, a little black thing by the lock with one screw and a chrome thing with 3. The place where the seat adjusters are, pop that out with a little screwdriver, and another bolt is in there. Remove the panel by the outside mirror, if its manual mirror, then the adjuster too. I think thats it. Then just pull up and out on the whole thing, in that order.
#3: Renntechmercedes.com probably has somethin, I think bergwerks.com has something too, I dunno, I dont have ASR.
#4: I got a new head unit, speakers and a 10-disc changer.works and sounds great, i thought the original was obnoxious. With the left side not working on radio, uhh... it seems like its probably in the wiring, I guess? Mine was out when I installed the CD changer but I fixed it something wasnt connected, why its only for the radio is weird.
#5: Wheels would be fine, I've seen some CE's lowered with 19, you can put what you want on there. Offset is supposed to be on the rim someplace, but I've never seen it.