Here's what I suggest:
Find an independent specialist! If you're a PCA member and attend any of the events, it shouldn't be too hard to find a recommendation. They will be cheaper than the dealership (no matter what discounts you stack up). Chicago has got to have plenty of specialists.
Midwest Eurosport
104 West Irving Park Road
Bensenville, IL 60106
(630) 595-5577
Vaia Auto
860 West Lake Street
Chicago, IL 60607
(312) 733-0076
Euroquipe
601 Sidwell Ct. Suite I
St. Charles, IL
60174-3415
(630) 377-3774
I found these first 2 from this list. The shop I use, and love, is also on this list (if that establishes any credibility). Found that last one on Google.
I am prone to bash dealerships due to their dishonesty and high prices (not just Porsche Dealerships). I hear complaints about customer service frequently too. All in all it doesn't add up to favor the dealerships. Ironically the 2 times I've taken my car to a dealership, they were quite nice and did the (minor) repairs for free. (Plug: Boardwalk Porsche, Plano, TX)
That my best advice. I don't know the answers to your other questions.