Did they do similar studies, simulations, or whatever for other energy sources?
Yes, they do similar maps for wind, although it's trickier, since wind can vary widely with local topography.
If so then why no mention of them?
Can't study everything at the same time, the report would be ten thousand pages long and somebody would still say "but why didn't they study X?"
I'm getting the impression that lowering CO2 emissions doesn't rise to the same level of concern that it used to. What I'm seeing as a greater concern is energy costs. Can we run this mapping to optimize for lowest cost? Then maybe put some kind of dollar value to CO2 emissions, or some CO2 value to energy costs, to get a map that is some weighted average of the two?
CO2 emissions decrease equals the solar energy output times the carbon intensity of the power grid at that location (ie, how much CO2 is emitted per kilowatt-hour generated by the utility. Highest for coal, lowest for hydro.)
You could do price, but that can be changed by the regulators. (in particular, changing to time-dependent power cost changes the economics of solar radically. Also changes the economics for coal, gas, and nuclear.)