Sinead O’Connor was excommunicated from the Catholic Church for trying to become a priest, so no, she wasn’t Catholic. She died a Muslim, and probably would have preferred we called her Shuhada.
In reality she stopped being Catholic long before she ripped up a picture of the Pope. For more than 25 years she was Catholic only in a definition that would also include me - having been baptised as one. You seem to think lay Catholics have influence on the Church. They do not. Only in the form of donations, which practicing Catholics have never withheld. So I’m perfectly fine with the Church using those donations. Where else is it going to get money? Selling priceless artifacts?