> 2) Books are counterfeit
> 3) Books were purchased through "unauthorized" channels, e.g. free review copies
> None of these is a problem with the Amazon buy box.
Perhaps in your experience, but that's not the case. Counterfeiting, at the very least, is an actual current problem on Amazon for all sorts of items, including books.
Used, stolen or grey-market books are also not beyond the pale for unscrupulous sellers.