I firmly disagree.
The supercomputer wouldn't need to know about psychology, sociology, politics, etc.. Really, all the computer is doing in this model is tracking the world's resources, and orders for the most part. In a Resource Based Economy there is no currency. Somebody would put in their computer at home I need a hair dryer. This is sent electronically to a computer, which then packages the hair dryer and records the inventory. This data is sent to the Big Super Computer let's title it, and it records the consumption of the resources that was used for that hair dryer. That is essentially all it is doing. Sure, there are billions of people on this planet. So let's say everyone wanted something every second and put an order in on that second. That is 6 billion orders per second. Let's say it takes the processor(s) 4 instructions per order. Let me double that. 8. That is about 48 billion instructions per second. As you can see, this is very feasible because these are processor speeds for a singular computer.
Instructions per second - Wikipedia, the free encyclopedia
If you notice, the Intel Core 2 Extreme QX6700 (Quad Core) 49,161 MIPS at 2.66 GHz could handle that load, and this processor was made in 2006. On top of that, I'm sure we would be able to link multiple computers together and combine the resources. So really, this is very feasible.
I am not even going to waste energy on the other point.