Met a person at the airport in 2016, he had more than a year overstay, I had a couple of weeks if I remember correctly. We both had valid tickets to Norway. They followed us over to pay our overstay. We both paid our overstay, he got a bunch of documents and a stamp about his 3 year ban. Then they showed us where to go to our gate. He was not arrested and left
I know people that is here on ED visa and have been 6-7 years. And the plan I showed for my visa doesn't say that I study 8 hours a week, I only study 4 hours a week.