Do you really want to get me started on this? It could get long...
Creating demand for Th is GOOD. You get it anyway while mining for RE's which we need right now, might as well use the stuff, else it's a hazardous waste.
The glossing over by just stating some numbers in this amounts to telling a lie by leaving out a ton of the truth.
Several points. Th232 isn't fissionable. It's an input to a breeder that makes U233, which is about the best bomb stuff there is - and the most easy to separate from the waste. Ponder that. No centrifuges required, just "simple" chemistry (on some very hot crap, has to be done with robots at a distance, but still - simple).
That low number for utilization of uranium is true, but also untrue. Here's the deal.
When we decide to not reprocess fuel (due to the proliferation concerns like the above), yes, we only get a little of the energy out of the U. There are a couple reasons that Fukishima amply demonstrates. After some running, a fission reactor has built up, guess what, a buncha fission products (you hear about Cs137 as a biggie, but there are a lot). This means that even after you drop the control rods and there's no fission anymore, all this hot decaying stuff still creates heat that there is no way to turn off (other than waiting a long time, which is what they do when they stuff used fuel rods into pools - they are still so hot, radioactively and thermally, you can't process them again for a few years with any tech we have - too dangerous). That's not the only problem. Some of the things that build up as reaction products absorb neutrons, and thereby "poison" the reactor - after long enough, you can't even make it go critical anymore, unless you designed it to be damn dangerously (potentially) over-critical before this crud built up. So they don't design that way - they are trying to be safe the best they know how...(which could be argued either way how well that is). In the end, it comes down to how continuously responsible a set of humans can be, or become - taking human nature, greed, profit motive etc into account. The balance might not be good enough for we teenagers (as a species) yet.
The breakdown products from fissioning U233 are different, and it's a separate complex study from what you get from burning U235 while also breeding Pu239 out of the U238 always present (except in bombs and research reactors...).
But they are still there, and big time - the devil is in details I'd have to go look up to be sure about, but you're going to get nearly the same series of junk as byproducts, still have the excess heat even after you turn the reaction off, and nope, just dumping the molten salts into a different container doesn't fix that problem.
So, feasible, yes, desirable, maybe - we need energy, and Th is not only cheap, it's otherwise a problem we need to find a way to use up or get rid of. The problem of handling the thorium "waste" from RE mining is why we let China have that market back in the day.
But statements like "we'll never run out" - heck, that's an obvious falsehood, and things like that make the rest suspect.
Right now, only India seems to be interested in making mixed cycle Th->U breeders, and they are moving pretty slow (probably a good thing, this stuff has dangers and it's good to be careful).
Note, I've recently joined up at google plus and been having a ball over there. I'm signed up to do an official show Wednesday nights at 6 pm EST, as "Professor Doug Coulter" and am taking all comers questions and trying to answer them. We did a dry run last Sunday that brought in a huge crowd, and I went 5 hours and made my brain sore, but we had a ton of fun. For the first one (next week) we plan to do almost the same thing - which will include a demo run of my fusor and discussion of that and whatever Q&A the audience comes up with.
Kind of like being half a talk show host, half guest, with the entire audience interviewing you. There's some other smart guys out there too...fun.