A few things here
- cummins engines are all "broken in" at the factory before shipping to Chrysler. It's already had its break-in oil change
- use whatever meets the spec requirements in the appropriate weight for your climate. Cummins is in bed with valvoline so that is what they recommend. The new engines are roller cam engines and have more stringent requirements than the flat tappet engines, so don't just dump whatever 15w40 you have laying around in there like you did with your older 6.7's.
- don't bother with a magnetic drain plug. The things that might plague the engine oil sump are non-magnetic. Keep the factory plug, torque to factory spec, don't worry about it. If you start getting iron in your oil pan the engines already dead anyway. I generally use valvoline 5w40 in the winter and rotella T6 15w40 in the summer in mine. You should peruse bobistheoilguy if you really want to nerd out on HDEO. Personally I don't think there's much to it beyond using whatever meets the appropriate spec.
- if you need something to worry about, it's the fuel system. Be militant about your filter changes, water draining, etc. Use factory fleetguard or Mopar filters only.