THIS. Where does one draw the line, indeed? I have my opinion on which of your listed scenarios are reasonable or not.. as do you.. and the next guy. It is likely we all disagree. Which one is 'correct'? Who can say? This is why I would always rather er on the side of freedom when it comes to individuals and privately-owned corporations. What is it to me if person A or company B doesn't want to do business with me? Fine. I'll do business with somebody else... The story is different for publicly-owned corporations and government agencies. People like to trot out the term 'Jim Crow'... But they seldom mention the next word in the phrase... which is 'LAWS'. 'Jim Crow LAWS' were passed by government dictating that business MUST discriminate by having things like separate white and colored water fountains, separate white sections and colored sections in restaurants, etc. FAR from being responsible for these problems - Churches (religious people) got the ball rolling to abolish slavery in the western world... and indeed churches were first and foremost among the leaders of the civil rights movement in the U.S. These 'Religious Freedom' laws being passed bear NO resemblance to Jim Crow or other times of discrimination.
Anti-discrimination laws are not a problem -IF- the vast majority of the people and the culture already are of that mind-set. This is why legislatures pass them... because the people WANT them. The present quagmire in the U.S. comes from a tiny minority of the population attempting to hijack the court system into getting their preferred anti-discrimination ideas imposed as defacto law without having to win the hearts and minds of the general population. When unelected judges impose their arbitrary will on the people absent representation of any kind - regardless of the subject-matter - bad things are going to happen.