No idea of the 750, but there seems to be a lot of corrosion on various Citations in Europe, Cessna blames the runway de-icing agents used by some airports in Europe which are more environmental friendly (apparently...) and thus lack an corrosion inhibitor that is contained in fluid used elsewhere.
Dunno for the rest of the fleet, but the Inspection Doc.42 on the 680 shows that we are in a "corrosive environment" in Europe, thus we have a corrosion check every 6 months. There are several SILs on the subject as well. cessna recommends washing the airplane as soon as possible after flight/operating in suspected corrosive environmment.
We have ours threated with "COR-BAN" which should protect the caves better. (thats what Cessna says - time will tell)
Ours had no signs yet (5.5 years old, roughly 1450hrs), operated in Europe.
Cessna says other manufacturers do have the same issue. (do they?)
Paint quality has been an issue with Cessna in my experience, but I had huge chunks of paint fly off a Challenger 300 as well. I guess the experience with the old primers, colours etc. is all out of the window and we relearn on the newer, 'greener' stuff right now.