Sometimes it just makes sense to trade up if the diesel doesn't fit your needs anymore. I've looked at a new GM 6.2L Halfton but it's hard to get away from the diesel engine. Love the sound and power!
Usually tuners use this software to remote into a PC and help run the provided software to tune trucks... but, I wasn't aware you could tune a EcoDiesel via the OBD port.
If it started just after the fill up, you either had bad diesel or pumped gas into the truck. Otherwise that's just bad timing. If it's bad fuel the stations insurance should take care of it..
I would question your extended warranty on why it will not cover your current repair... sounds like a...