It depends on your definition of “minimum wage. The real minimum wage is what people can realistically afford to earn and break even. If you can afford to live like a chinese farm peasant, then you can afford to work for a buck or two a day. If you live in the US, you have to earn more than that just to cover taxes. If you can convince people to work for you (outside of illegals and H1-B workers) for less than minimum wage, then go for it. But you’ll get what you pay for.
It depends on your definition of "minimum wage.
Already given (see above).
The real minimum wage is what people can realistically afford to earn and break even.
That could be called a 'necessary' wage, but in no sense is it a minimum.