First, welcome!
Regarding your fiance's Saturn, if the dealer installed the items, they should have checked that everything worked properly, ie; calibrating the onboard computer.
I don't have any experience's with turbo's, but I've perfromed similar mods to my SS, and other than an issue with a catalytic converter, I haven't had any problems. And I'd be concerned with the smoke you say you saw at 20 mi.!
Personally, I'd get the car back to the dealer ASAP. They sould check that the mods. they installed will not adversley affect the car.
I hope that was of some help?