“The interesting question is this -— is it the role of government to make laws to FORCE actors acting within the marketplace to ACT MORALLY?”
It depends on what you mean by “within the marketplace”. If this excludes violence, fraud, and other means of coercion, then no. Even if they go beyond this point, general rules—or the original meaning of “regulation,” that is to make regular—aren’t so bad, as long as they don’t impede efficiency.
The important point is that government absolutely has a mandate to impose morality on the marketplace. It’s just that the morality they impose ought to be the one that’s most conducive to economic prosperity. But I don’t want to encourage our dear leaders to run a magnifying lense over the economy to determine what is and is not most conducive. The best we could hope, if we leave them to their whims, is a rational utilitarianism, which is bad enough. That’s why we gift them with the laissez-faire mindset. Give doing nothing the benefit of the doubt, always.