Glancing over these calculations, they seem very well thought through, however a very significant error is present at the very beginning of these calculations: Molten Thorium Salt increases the Factor of fuels inside it. A fuel with usually (i.e. in water, gas or molten chloride coolants) having a Factor of 1/3 will have a Factor of 1/2 in Molten Thorium Salt.
That is a quite significant boost and from my calculations I used to balance the coolant, should more than make up for the thorium used, but I don’t want to rob you of doing the calculations here yourself.
Molten Thorium Salt is an extremely powerful coolant, however only when used with the best (in terms of Factor) fuels. It has the advantage of burning thorium very efficiently and fast (fast being significant, since thorium at maximum efficiency burns really slow, requiring a lot of reactors to get a decent power output) and reactor designs being very compact. Another huge benefit of Molten Thorium Salt reactors is not even needing a heat exchanger and a boiler, since the reactors with the absorber rods can use distilled water directly outputting steam.