As I live in another part of city since last Wednesday, I also have to find new ways for my bicycle. I know how poor situation in Prague is, but I hoped that marked way I noticed while moving will be good for travel to work.
But it looks like expected too much. Maybe somebody forgot to tell people marking this way that most people don't use bicycles on stairs. I don't know why does this way in about 3 kilometers I used it go over three stairs.
If you want to go through Prague on bike, forgot to use marked ways, you will most likely end with troubles. Better find some local people who will guide you.