I'm not sure, but on Friday, It's a bridge day and I think it is like at Europapark that it will be crowded on this day! But you can buy the fastpass there. I recomend you to ride Krake first, then Flug der Dämonen. Krake has a small capacity and the longest line. If Scream is open, ride it in the morning or in the late afternoon!
I hope I could help you, but I don't really know how the crowds are!