So sorry to hear that, it sounds like you are getting a new engine though. I hope they get one quickly and are able to get you back on the road with a great engine and quality workmanship!
I have had every recall completed in my 2015 and been participating on Eco Diesel forums since my truck was new. I have NEVER heard of any oil lines getting replaced. I think your friend is wrong.
You can also use a high temperature silicone hose. If the first hose lasted close to 100,000 miles you will probably get at least that again out of an upgraded hose...
There is really no way find out whose tune you may or may not have. Sometimes you can identify if you have a tune by trying to set the cruise control at less than 30(?) mph.
Many generic or sub par tuners will also program out certain error or engine malfunction codes.
In my novice opinion...