> Hospitals in the USA marking stuff up 500 or 1000% ARE harming society already.

Agreed, that needs to be fixed.

> If all shoe companies charged $400 for a $2 shoe, I believe society would be harmed, yes.

A competitor would step in, charge less, and win the business. It would only be immoral if competition was quashed or impossible, such as in a hoarding situation.

> If every company hired people as part time only so they didn't have to pay benefits, again, society would be harmed.

I don’t see why this is true. The only benefit of moral significance is medical, and there’s no law of the universe that states that must be paid by an employer.