Prymancer has shown that people can be offline for years and then return, but I would agree with this for the most part. I really dislike that hugegnome left his land like pure trash, makes Times Square look messy. I also dislike the land to the right of his with the acid on the floor and the single note. Since spawners cost crowns, what Mike could do is give players a 30 day warning to remove all spawners in the main markets then they're removed to free up space. It's how I got my land through the Inhibitors being removed a year and a half ago.
Crystal King is a good dude, I'd say him and I were the closest. Around last Christmas he created an alt forum account apologizing and wishing everyone a Merry Christmas. I had no part in whatever he did to get banned and I'm still a bit confused on what happened.
The paintings you find in chests are called Landscape and Smasheroid, they aren't very rare paintings. But the best chance at finding the ultra rare paintings are through painting bunkers which are randomly spawned throughout the world.