I think it's worth noting here that the Masterpiece Cakeshop ruling wouldn't really have any bearing on most of the scenarios you described even if they had ruled decisively one way or the other. It's already illegal to discriminate on those grounds you mentioned in those cases. Even if they wanted to deny you on religious grounds, if it were for a more standard commercial transaction they would totally be in the wrong and lose big in civil court for that. What made the Masterpiece case unique was the question of where you draw the line between equal protection and freedom of expression and freedom of religion.

The problem is that while the 14th amendment guarantees equal protection, the 1st amendment guarantees freedom of religion and freedom of expression. That's why religious orgs, and religious people, are sometimes allowed to discriminate in cases where they normally wouldn't be allowed to.

And while it may seem unjust, you do have to draw the line somewhere, otherwise you're not respecting the 1st amendment at all. The extreme case of forcing a pastor to host and officiate a gay wedding is an easy one to resolve, but the line gets murkier as you move away from that, and honestly it's hard to call one way or another with the Masterpiece Cakeshop thing.

The problem is that there is some degree of "expression" in making a custom cake to congratulate a newlywed couple. The case was in part about what degree that "expression" plays into established law on commerce. Again, in most cases this wouldn't give religious bigots a right to deny anyone. They couldn't refuse to check you into a hotel, for instance, because that's not some kind of tacit "endorsement" of your sexuality. It's just because this is a custom-made wedding product and there are religious objections specifically that it became a case.