The wheels had nothing to do with the CV joints, most likely its just age, as the boots crack over time. Don't worry about the diff either, as the wheel size is not going to damage that either. Although, if the wheels/tires are too big (i.e. larger total diamater than OE) then your speedo is not going to read the correct speed.
You did not mention what size tires you have, but you should be running 215/40/17, which is the best size to avoid rubbing. The 215/45/17 is the recommended size (Tirerack, Bekkers) but most likely will rub with the Sportline suspension.