I have been thinking about about SE's press conference and how they want to make they game good for casual players as well as hardcore players. I think the only way to truly do that is to have offline content. Since it can connect online you will be able to update the adventures and keep the experience fresh. Also you can pause. You can't get anymore casual than that.
Since there won't be "xp grinding" you can gain skill, (or whatever you will be gaining) offline and then log in to transfer it online. That truly would be the best Final Fantasy game than.