I have worked on the E450 and E350 Chassis (busses) now for 12 years. They are a GREAT chassis. There are not too many problems I run into with them. I have a lot of drivers tell me they get unwelcome heat from the drivers floor area, but have never found anything other than the dog house not fully latched. My guess is Ford is aware of a problem and thats how they were to find it so easily. Hopefully your all set.
When it comes time to have the ball joints replaced, DON'T buy the expensive dealer ball joints, get the inexpensive ones from NAPA and never replace them again. Other than that, you can expect MANY years of life from that chassis. Heck, on the newer models (like yours), were getting about 80,000 miles (mostly all in one county) before there due for brake pads...
'97 Jayco Eagle 314BHS
'03 Tahoe LT 5.3L