As the rest have said...the CF is not gone, it is just not in the lungs anymore (although, just like any other person, it is still possible to get pneumonia and whatever). In my case, the CF is also no longer in the liver since I got a liver transplant too.
As for your other questions...I no longer take breathing treatments or do CPT. I still take enzymes and a bunch of other medications (like the anti-rejection meds, prednisone, and an antibiotic). The CF will never get into the donor lungs but there are other things that can go wrong (like rejection and infection). Those are now my main worries along with cancer (caused by meds or too much sun) or my kidney's failing.