1) You can make money using your gem runner and selling the gems
2) Merchants restock when you gain a new level
3) Food is useful when you are not fighting. You can eat food between fights or when you hide.
4) Potions are more effective out of dragon form. Change to human form use a potion and then change back to dragon form.
5) If you need help with quests your options are search this forum for answers. Almost every question has already been answered. You can also ask new questions as often as you need.
There are also websites with guides, hints, and walkthroughs:
http://guides.gamepressure.com/divinityiiegodraconis/http://divinity.wikia.com/
