Welcome, darko. I have found that my cycas go through a kind of season when the outer leaves yellow and die. And a new flush of growth begins from the crown. That pattern appears to be normal.
I do not recognize what the white growth may be. But if it were my plant I would treat it as a fungus to start. I would take a tablespoon or so of baking soda mixed with a quart water and spray the plant down. And continue as long as needed for quite a while. If it is fungal, it will make the environment uncomfortable for a fungus. And it will not harm the plant.