I'll add material to make a nice mowable slope. I built the pad up with shale and left it steep so the concrete trucks could get close and stay relatively level. I'll use a lighter clay/topsoil for the final grade. I also saved some shale to feather out the driveway.
Radiant barrier/ insulation. Something like below. The building manufacturer said he likes this better than the 3" fiberglass and it's a lot cheaper. Claims similar R-value but I have not been able to find much that backs up his statement. I've seen some say up to R-6.5, but the biggest thing is to reflect the oven effect in the summer and stop the sweating in the winter. If it's terrible I can add insulation on the interior also, but it's not planned as air conditioned space.