Sneaky pete

It looks like you covered all the bases. About the only thing left I can think of would be injector voltage,harness or bad new injector.

Motor mounts. Some of the earlier trucks had issues. Worth a look see.

GM uses the customer as R&D now. Don't fool yourself. The largest GM dealer in Fort Wayne In. charges you to check vehicle customer complaints with the vehicle under warrenty Total Bs . They will also sell you a vehicle warrenty that runs out when the factory warrenty does. What kind of honest company does this? Be carefully when dealing with GM.

Automatic car wash?

Sounds like a acurater or a stuck blend door. Probably acurater. Go through hvac settings to find out what setting isn't working. Get under the dash when making noise to find out which acurater it is. Good luck it maybe in easy reach.

33's fit just fine. On my secound set on a 2020 elevation. If I'm not mistaken the original 20in. rims are 33's bfg.

Compressed air,piston at top of cylinder.

You could use a dial indicator also.

Have you tried the switch on the left side of the dash. On mine you can turn the left,right or both on. Only works in park.

High pressure fuel pump. It sits in the valley at the rear. Normal

From what I have seen the thieves replicate the fob signal that is usually in your house. With a laptop they have to get close enough to the fob. That usually means walking around outside until signal is found. They'll take signal to the truck and take it. You can solve that problem buying a faraday bag to put your key fobs in.

Put in sport mode...

Put a clamp on it.

That looks like your front diff. vent. It should be up higher next to your coolant reservoir. I would move it up and zip tie it. Or you could leave it. Typical lazy tech

No