Quantities are therefore, large.
Percentage efficiency depends on when in the cycle you take the fuel out of the reactor and reprocess to separate the U-233. Probably 20-30% conversion is possible under the right conditions.
Time is months to a few years.
Generating U-233 in a Thorium reactor is almost a no-brainer. Handling it afterwards is harder than U-235 or Plutonium, but the critical mass is less than U-235.
This threat is not just idle speculation, and anyone who says that Thorium reactors can not be used to produce weapons is dreaming...
OK, last question.
In a “normal” cycle, is the U-233 consumed, or does it become a waste product requiring disposal?
The article seems to state that there would normally be no waste.