Since we are talking thermostat: the FTE forum noticed a hotter (215?) degree setting made easily noticeable performance and efficiency improvements and there are kits to change over.
Should be able to see the stored odometer reading in Forscan or Torque pro, I just don't know the PID request statement.
If you're going to run used trany oil, you will need an extra filter that does at least 1/2 micron otherwise you will fubar the injectors.
The owners manual is for people who never owned or drove a diesel and generates a overly conservative method of operation that normally would not break things. Proper ecomodding is so far beyond that.
Finally: consensus is: anything over 2000 rpm is a waste of fuel