That's awesome to hear! Yea, no doubt the 1500 platform rides so much better then the 2500's. My father in law has a 2022 2500 w/Cummins and it's nice, but rides like a log wagon. :D
Welcome to the forums!
Delete is simply people talking about removing emissions components. Illegal, but so is driving over the speed limit. The tunes are different levels of power.. stage 1 is generally a lower power over stock that people use for towing/etc.
A few articles around that one:
https://www.ecodieselram.com/forum/threads/hi-everyone-i-am-new-to-the-forum-i-own-a-2015-eco-diesel.6324/#post-43091
https://www.ecodieselram.com/forum/threads/p20ee-code.4653/
Off the top of my head, I know rough country makes one. No experience with it however...
https://www.roughcountry.com/dodge-ram-rear-led-bumper-10775.html?find=2017-ram-1500-4wd-755136