Sorry, but that's just wrong. There is no such thing as 'watts in the wall', except at the final wall. There's a big cost to transporting energy at low voltages, and another big cost to combining lots of small generators into a big flow.
There's a reason we transport electricity cross country at 10,000V or more. And it isn't free to boost it to that point at the source, or downconvert it at the endpoint.
Since you've an educational background, why don't you just connect a battery to about a mile of wire and see what the final voltage is close to the battery, and a mile away. You get points if you are smart enough to use a very strong battery and very thick wires to reduce the voltage drop. Try again at 50 and 100 miles with any battery/wire you want to use.
The engineering of electrical transmission and distribution systems is a valid place for argument. And we do it from big plants because it's cheaper than from lots of small plants, for numerous and technical reasons.
Both small and large plants encounter NIMBY & other political problems, so we can leave that out of the mix. Wait until you try to put in lots of solar units or transmissions lines in a politicians back yard.
Malarkey. A 500MW solar thermal plant is in no way different from a 500MW nuclear plant to the "end user" as far as the "density" of the power is concerned. 500MW is 500MW. Any "tranmission" issues are completely identical, because the actual gizmo that cranks out the watts is exactly the same for both plants---a steam turbine.
The only point you raise that has any validity is the one about "NIMBY", which is right on target. If you "had" raised the issue of "cost to implement", you would have had a second valid point, but, as with any other technology, an increased demand and mass production of parts will bring the price down.