[aardvarcus]

Well, here is some hopefully helpful advice for your project.

Good job pulling off the roof rack, I never cared for them nor the desire to add them and load them with heavy cargo raising your center of gravity.

You mentioned building a house, I hope you are planning to insulate it well to reduce the amount of energy used by the house. (Note you don't have to use new/fancy methods to have a well insulated house.) I built my own house (myself, not paying others to work) so I understand about needing a capable vehicle to move materials, often with limited notice.

I did the small commuter car/ heavy truck thing for a while, ended up not being as big a benefit due to constantly taking the truck because I needed to haul more than the car could. I moved on to trying to build a reasonable MPG vehicle capable of hauling a reasonable amount. I end up using less fuel on an average weekly basis overall this way.

I have a build thread on here, 1994 K2500 4x4 Suburban. I was daily driving it a 55 mile each way commute, getting mid-24s for MPG. Mine is not nearly as aerodynamic as yours (yet, big things planned). I am temporarily driving a 4Runner until I can pull off a few more mods and get some of the creature comforts installed in the Suburban.

I would suggest reinstalling the air dam, mine handles much better with the air dam. I made a custom conveyor belt air dam for mine, higher in the middle but lower at the edges to kick more air away from the tires. Tire deflectors will help you. The exhaust is a huge issue with the belly pan, be extremely careful or you will create an oven (with your gas tank inside). I eventually plan to belly pan mine everywhere except the exhaust, but am running an air dam until I have time to pull that off as it will be a large undertaking.

Edit:
I would also suggest keeping the mirrors (or installing smaller mirrors) but add a panoramic backup camera and/or passenger blindspot camera. The comments about the Tahoe Hybrid parts are a good suggestion if they fit yours, the ones that can easily be sourced and swapped especially any that improve aero in the rear should be on your short list.