Update:

Got truck back from dealer this afternoon. Here's the results:

Wobbling belt tensioner is normal. First bearing with 0.125 runout I've ever seen that was "normal".

Overlaod pads replaced with new pads plus slip on cushions and spring leafs re-aligned.

New rear shocks ordered.

Under hood weather strip re-secured.

Excessive transmission downshifting and hunting determined to be possibly caused by defective fuel temp sensor. (Code PO181) Sensor replaced and tested OK. They still insist that there are no available software updates for my truck. This discussion wil be continued when I go in for the new shocks.

For what ever it's worth, it seems to have smoother power delivery and better response at the low end. Just seat-of-the-pants observations. I'll see what happens next week when I hook up the trailer and run 1500 miles at 16K GCW.