It has not proven to be a huge proliferation risk, France and Japan both reprocess fuel. That fear has so far been unfounded.
Even if you still want to use non-proliferation as a reason to not process fuel it is not an issue with Thorium cycle reactors since no plutonium is produced. .
Solar is an opportunistic source of power. You can use it to replace some peaking load when available. It is not effective as a baseload.
Wind is better but still requires peaking style backing plants.
It maybe that large scale thermal solar plants have too high of an ecological impact but those issues are not found in pv solar plants.
People need to stop advocating for technologies and start advocating for solutions.
The fast path to low carbon energy independence for the US is to replace coal baseload plants with nuclear and build solar and wind.
In the short term electricity base load should come from nuclear, hydro, wind, and natural gas.
Peaking from natural gas plus solar when available.
Medium term Baseload Nuclear, hydro, wind. Peaking natural gas, solar. transportation fuel reformulated natural gas.
Long term Baseload unchanged, Peaking synthetic CH4 and H2 plus solar, transportation reformulated synthetic natural gas.
I left out electric from transportation because while it is practical for trains and cars "if the costs keep coming down" it will not be for ships, trains, and long haul trucks. With enough cheap energy it is possible to make CH4 from the air and water and then make that into diesel and jet fuel.
Of course very long term we may get fusion and or super batteries that will make storage more practical but they are not here.