> Thorium reactors and newer designs are incredibly efficient

not where is counts. They aren't economically efficient (Expensive)

>I love renewables, I'm ready for them, however can they handle peak loads?

when enough are deployed, absolutley. There are plenty of countries where they already do.

>Can they keep a stable output 24/7?

Again, yes they can. Have a google of Costa Rica or Portugal.

>We have to store excess power to help during peak loads

Sure, we have to do that now too. Nuclear also requires you to o store excess power to help during peak loads because you can't economically operate them in a flexible manner.

>what technoligies exist that's cost efficient and as good or better than just running a few nuclear plants in a region?

Literally all of them. Have a look at some actual recent numbers. Even Residential Solar is now the same price as nuclear.

>Electrcity transmission for a country is complex and daunting and there's more to it than just "Plop some more turbines and solar panels".

Sure, that's a nice red herring. Let me spice it up:

Electricity transmission for a country is complex and daunting and there's more to it than just "Plop in some more nuclear plants".