So suppose a business owner wishes to avoid being on the "naughty" list, and informs his employees that they MUST wish customers a "Merry Christmas" regardless of the religious beliefs of the employee, or else. How do we feel about that?

I'm not real happy with the thought of people being forced to violate their personal beliefs in order to hold a job, as long as the keeping of those beliefs doesn't violate anyone else's rights. (And it's hard to think how not being wished a Merry Christmas violates anyone's rights.)