Hey unit,
yeah the only thing that changes when you select a goal/ quest is that you will see the distance and dirrection to the location of the goal on the minimap. The system is already setup to complete subgoals of a quest that is not selected currently.
I will not add item rewards since that means that i would have to integrate an inventory/item system which i already did in my first tutorial series. The timer thing sounds really good actually and i will try to add that in a later episode. The rewards are already completely optional (just leave them at 0 and you will not receive anything). By the way your journal layout looks fantastic and thanks for the link ^^
For the goals box you do not need a scrollbox since the goals box i a child of the QuestDetailsBox which actually is a scrollbox. That means that there is infinite space for the vertical box (goals box) and because of that we do not need another scrollbox.