that screen is always up , i flashed mine to stock the day before a service visit and that screen was on mine as well in stock form. also the procal said locked i am sure it is locked to the VIN once the voucher is used to downlaod the tune to it.
its doable without jacking the rear up, I did my fox 2.0 rears in a parking lot, I just removed the spare and use a cheap ratchet strap to compress the shock since I was working at a bad angle. I still get the side to side rocking but going over bumps at speed is more controlled on the rear...
I would suggest to do most of the install yourself up to the point of flashing the updated tune to the truck, let the dealer do that, if you choose to have the dealer install, that way the voucher # and Account are registered to you and not the dealer and you can update the tuner in the future...
If I had your level and tires my truck would be your twin. I have the same grille.
I am waiting for my stock tires to wear out before doing bigger tires and level will most likely do both at the same time, which level did you go with?
that will leak, my leer is the same way but the flap sits on the outside I bought some neoprene foam to seal the top of the bulk head I just haven't had a chance to install it it.