Disagree. Bluesky is a political circle jerk echo chamber designed for weaklings who need authorities to hold their hand in the face of dissenting opinions.
Yes, because insurances don't have them valued, they just trust owners for the price.
Then it's even more profit because they get to keep the paintings to insure again, sell again, or put them on display at the owner's house? I'm not sure it's that easy to get away with.