I take it you're on mobile? In that case I'm afraid I can't help you, because I'm only on PC.

I don't know whether it's possible to bulk-block communities, but if you click on an individual community, there's a box on the right with the name of the community, Create a post and finally Block community. I've just clicked on the latter and it seems to work.

I'm feeling so very called out by pretty much that entire pic.

My (neutered) boy, Silky, absolutely adored tummy rubs. Not just chest, but actual lower abdomen. He'd purr his head off and streeetch (and drool, after FORL destroyed most of his teeth). As far as I know he was just a regular moggie - he certainly didn't come with papers from the shelter!