Going to try for a new tow vehicle

Start it up and drive. Fuel injections, you don't need to warm them up. The computers will adjust the fuel and air on a cold motor, but on the Turbos, after a long or hard drive, you should let the motor idle a little before shutting down to cool down the turbo or turbos. The biggest difference between the turbo diesels and gas motors is the turbo ones takes a second or two to allow braking on a panic stop. Oil and fuel maintenance are different. Follow your book for details and you will have a 300,000 to 500,000 mile truck. Note: Use good fuel and not Bio fuels.
I disagree with your comment on braking. I’ve had 4 Ram Diesel pickups since 94 and don’t ever remember having a braking issue with any of them. My wife tows a 25 foot gooseneck horse trailer with ours and believe me if there was a braking issue with it I would have heard about it by now. Plus a manufacturer would not be allowed to sell a vehicle that had an 1 to 2 second lag in braking.