Jim, here's a list of sensors that DDEC uses to control engine performance.
Your coach should have DDEC III.
1- TBS - Turbo Boost Sensor
2- Fuel Temp Sensor
3- Air Temp Sensor
4- Oil Temp Sensor
I would want to monitor other parameters also, coolant temp, oil pressure,engine rpm, etc.
I know nothing about the Silverleaf product, I only use my Pro-Link or DDDL to do my diagnostic work.
You mention that several sensors seem "flaky", can you be a little more specific?
I recommend to check all sensor connections and the two 30 pin connectors that secure to the DDEC computer.
I have found the wiring harness on the vehicle side of the ECM (side closest to the transmission on your coach) to sometimes be damaged, worn insulation, wires broken inside the insulation. Give it a real good inspection.The engine harness side usually is in good shape.Fixed a few tachometer problems this way.Hope this helps you.
Send e-mail if you need more info.Good luck.