I still don't get the economics of this relative to utility-scale. It seems like a great idea for social justice though, so I'm all for it.
There's no way the installation process is going to be cheaper on a house than on a plot of land out in the country. When you're setting up megawatts in a field, it's pretty simple. Setting up kilowatts on each of thousands of homes is a lot more fiddly work, each project similar but slightly different.
The data is not there yet, but you are probably right that a mega-installation has less direct costs than loads of little installations.
I guess one has to move from micro-economic to macro-economics and what we used to call in the 1970's Cost-Benefit-Analysis (a useful approach to look beyond the project to society as a whole but discredited by politicians throwing untenable assumptions about costs and benefits to wider society). This throws up a load of questions.
1.
What are the real costs of nuclear power from inception to final decommissioning of the power station not included in the table above?
Ukraine (Chernobyl) and Japan (Fukushima) suggest potentially large. The UK is going to spend an estimated USD 15+ billion for a depository of hot radioactive waste. In the US of A there is an underground facility somewhere in the West (near the Colorado river?) where an unknown but vast amount has been spent (as yet unsuccessfully) to safely store radioactive waste from their nuclear weapons program. There are electric utilities in the USA who are due to close down nuclear plants. Have they provided sufficient funds for decommissioning or will they choose Chapter 11 and dump the cost on the taxpayer ? Ask Sleepy about Sweden - another sorry tale to tell.
2.
What are the real costs of power from oil, gas and coal from inception to final decommissioning of the operation not included in the table above? How many coal companies have dumped the cleaning up of the environment on the taxpayer using Chapter 11 or flogging the business to Fly-by-Night Inc? Who will pay for the disposal of 35,000? redundant and abandoned oil and gas installations and pipelines that already exist ? How will Canada ever clean up the mess in that huge area when the tar sand thing is finished (hundreds of billion of dollars?) ?
And who will pay for the environmental cost of CO2 emissions leading to 1, 3, 4 degrees celsius of additional increase in global temperatures this century?
So, the true cost of fossil fuel and nuclear power generation, in my not very humble opinion, is far, far above those figures quoted in the table.
There are other benefits in home-based PV power, but of a more unquantifiable nature - e.g.s as you said - social justice, and just by existing making others think about going in to renewable, and in sparsely populated areas, perhaps reducing the scale of the required grid. But perhaps they do not belong in your table.