Nobody has ever been convicted for making performance art in a shopping mall

Courageous to make that claim. I doubt that you could substantiate that. Care to try? Fact is that artists and political activists get kicked out of shopping malls. And if they don't comply, they are prosecuted for trespassing.

So you would be fine with expurgating every reference to religion from the law of the land, except to include it along with race, gender, (legal) political views, etc. in such general protections?

Provided that the power of definition (for instance the significance of the pig) remains with the religious community. And you can't do that without a reference to religion.

Earlier you argued that driving a pig into a synagogue should be a crime because it was a pig and a synagogue. And not - or at least not exclusively - because of the disruption of a public gathering or the obviously threatening intent.

Exactly. I insist that the religious community makes the rules. A dog in a synagogue wouldn't be a friendly act either, it could even be more dangerous than a pig. The obscenity screechers chose the altar, not the western end of the nave. All this has no significance to the law  of the land, but to the law of the community.