When i download a story, do I still need to unlock each chapter or will it be unlocked once the story is downloaded?
Dowloading
You will still have to download them by yourself but don't fret as they have added a function 'auto unlock locked chapters' which quite useful since it can be turn on for specific story(ies) you want to without affecting others. As my memory serves right, locked chapters will be unlocked once you reached the chapter before it. I hope my answer helped you.