LakeBum, I'm not sure if there was a 'lack of maintenance' before you bought your coach but at only 32,000 miles, it didn't sit totally unused.
We did not have your experience with our Cummins in our 2008 Dynasty. I did have to have 4 replacement coolant boxes counting the original (apparently defective), the 4th box was the charm. Boxes one and two were under warranty. We drove that coach for 7.5 yrs. and just under 70,000 miles.
We never had a problem with the DPF, all re-generations were normal about every 10,000 miles. I did have to have the Lippert pump replace for our leveling system and a hydraulic hose for one of the rear slides (long hose). I'm so glad our new coach has all electric slides and air leveling only.
Basically, you are having more issues then normal and hope that it all settles down.
Safe travels,
MM.