Regarding the group of rich people forcing their will on the rest through force. I’d ask how these people get wealthy in the first place. In the free market they’d have to provide goods and services that consumers desire and are ready to pay for. Thus they have to benefit society in order to get rich. Wouldn’t it be weird that those same people (after having helped society) would turn against the people whose lives they have improved? But let’s say they do. People would just stop buying their products and services and these rich people would lose lots of money and eventually it will be impossible to fund an army to oppress everyone. Moreover, in a free society there would be competing defense agencies, some of these would turn against these rich people if their costumers were ready to pay for this service. In addition, a great number of people would be armed and able to defend themselves in a guerilla way making it extremely difficult for a group of people to permanently force their will on the majority.