I agree with this, and am really not at all interested in "offense" as a valid legal claim or social phenomenon. That's not what this article is about.
What this article is about, is that it's trying to show how freedom of "religion" is actually a less universal freedom than what we should really be asking for.
I agree with your 5th sentence, that we should be free to believe or worship whatever we want or not. But our rights shouldn't just be limited to beliefs and worship. We should be free to do and think whatever makes sense to us and makes us happy, as long as it doesn't prevent other people from doing the same. But the Constitution, as it is currently written, does not explicitly call for that.
Instead, what the Constitution does call for is a freedom of "religion", which leaves it up to interpretation whether "religion" is meant to include all beliefs and resultant actions, or whether it means something more limited and stereotypical, for instance, whether it's limited only to those beliefs about a "God" or that correspond with an organized church or cult.
The New York Times actually published an article (1) a few days ago about how certain religious groups are starting to fight abortion bands on grounds of religious liberty. And the way they are going about it is by establishing certain rituals to go along with an abortion, so that it seems significantly "religious" enough to be protected by the law.
As someone who believes in a women's broad freedom of choice when it comes to abortion, I of course see this to some extent as a good thing. But I think it also begs the question: why do we have to play these games at all? If something feels important to a person, why do they have to prove that it's part of a "religion"?
And the reason is because of the way the Constitution is written. Consider if, instead of establishing a freedom of "religion" per se, we established the freedom to "think and act in whatever ways make sense to us in pursuit of our own happiness and well-being, except in so far as those actions might infringe on someone else's right to the same". If we used that wording, then we wouldn't have to do all of this posturing about whether it's part of a "religion" or not. We would instead base our decisions on whether it promoted happiness and well-being or not - which is what we've really been after all along - isn't it?
If the Constitution were written that way, it would provide all the same important freedoms that the freedom of "religion" provides, but it would also provide it equally for all people, in all of their attempts to find happiness in the world, rather than privileging certain worldviews that happen to adhere more closely to a more stereotypical or well-established "religion".
And when we center the "pursuit of happiness and well-being", as I've done in my suggested verbiage, then it also makes it easier to establish logical and predictable precedents when arbitrating individual cases.
For example, we obviously wouldn't force a black print shop owner to print flyers for the KKK, because the KKK has proven itself to be a relentless threat to black people's happiness and well-being throughout history.
Whereas in the case of a web designer who's been asked to make a website for a gay marriage, there is no such threat posed to the web designer. the only possible threat that they do face is an offence to their opinion of what a "proper" marriage should look like. But as you and I both agree, the right not to be offended by someone else's opinions or lifestyle is not a valid reality. But the potential to be denied a service because of the way you are is a legitimate threat to well-being.
Get rid of the freedom of "religion", and replace it with the more broad and universal rights that we've always wanted. That's what I'm suggesting. I'm expanding our rights, not reducing them.
(1) https://www.nytimes.com/2023/06/28/health/abortion-religious-freedom.html