I just use NAPA filters. Never had an issue with them and put a lot of miles on the trucks. Will another filter work better if I go 10k or more without an oil change, maybe, but I never go that long. I makes me wonder how much, if any, of engine life someone actually loses because of the filter. How many filters really give people a problem.
If your scan tool isn't detecting a bad module then there probably isn't one or your scan tool doesn't have that capability. If that's the case try and get access to one that can access the modules..
I say anytime you go with bigger tires especially 35s or bigger you regear. Also just get a custom tune. Now I know you worry about the warranty but I have had warranty work done and never had a problem. The work I have had done had nothing to do with the tune or gears so it was still covered.
Vaccinated or not you can still get it. Covid is going to be around for ever just like the Flu unless by some chance it burns it self out, but I doubt it because vaccinations usually stop a burn out. Humans will build a small natural immunity to help fight it off and treating it will get a lot better. People can either hide away at home never doing anything, or they can go out and live a real life. I say the hiding at home is worse then Covid.
I would move coil from 7 to another one and see what code comes up. When it comes to the shifting has it always been like that or not normal since you got the truck.
First thing I would do is ask the dealer how they came up with replacing those parts. Did certain codes come up? If so get the codes and check for yourself. A fuse popping can happen because of the smallest most insignificant thing.
Sounds odd to me. I have had mine submerged on multiple occasions crossing rivers with a trailer and have never had a problem. Also not having any blown fuses leads me to think something else is going on.
Definitely upgrade system. For a battery I would choose an AGM from ACDelco if not then XS Power, Odyssey, or Delpi. I think Optima quality has gone down now.