New, to me, 2022 3500HD Denali

I picked up the above truck last week from a family friend in Canada. < 21,300 miles and very well treated and maintained. It was built in Flint for the Canadian market, so has a couple things that are specific to that market and/or that model.

First, can the DRL be reprogrammed to the U.S. standard of them coming on when putting the shifter in Drive vs them being on any time the engine is running?

Second, can the mirrors be reprogrammed to automagically retract when the engine is shut off?

Third, non-Canadian related, can the truck be lowered? I'm very concerned about towing my fifth wheel and the bed clearance. I see there is a smallish spacer on the rear end, about 2", but didn't know if there are any other ways to lower it. My brother's '19 F350 only has about 5.5" clearance and his FW was hit by the bed of the previous owner's RAM when going into a gas station. We do like to boondock, and I'm used to 7-8" clearance.

TIA for any advice / info.

Lyle