If you own a person and can compel their work without pay, and buy and sell them without so much as a by-yer-leave, that is not a market-based system. Without choice, there is no market.
Exactly. In a free market, people freely trade their work for pay.
Wherever slavery exists, it exists because the government permits (or enforces) it.
His whole statement doesn’t make any sense. Does he really believe that “democratic” governments aren’t compatible with war, corruption, etc.?