you generally dont want to change the bevel on the edges so use scotchbrite to remove any surface rust, it will come off eventually. The board bag is causing it to sweat and rust, keep it in the open and run some wax over the edges to protect them from the moisture
I left it in the open in my room before and it still rusted so Im not sure. Okay I will keep it out of the bag. Ill keep it on the side. But why should I not sharpen my edges? Im not sure wether it is just surface rust anymore. I don't know. And whats scrothbite?