do some research through the Ecodiesel subforum. They have had their share of issues. The carfax will only tell you maintenance records (if they were shared by the business) and any wrecks. Good luck, hope you are getting a great deal on it. I've read enough on them that would make me think...
You will have no issues switching. In fact, you could change with synthetic one time and go back to regular oil if you wanted. But don't mix two different types. Just go with what Ram recommends for the truck. That is the main thing, stay with the weight they recommend.
I'm not sure exactly what you mean, but I assume you mean the engine is holding higher RPM's to keep the truck from coasting down a hill. Mine does this as has my last 3 vehicles. It lets the engine do the braking so you don't overheat your brakes. It's actually for safety, if this is what...
1. etorque (if she's used to the start / stop).
2. 20" better ride and cheaper tires
3. steps - absolutely needed for my wife to get in the truck.
4. I would stay away from the 12" screen, still seems to have quality issues.