Hint: Get cursed apprentice's magic back:
After completing the cave of Kapel you will get cursed and your magic will be taken away. You cannot remove your own curse without the moonlight. However, you can remove your apprentice's curse. Switch apprentices and fight until you find your old apprentice again. If he or she asks to join you again, their curse will be removed.

Hint: Guntz: Power Seed:
The first time you go to Guntz, enter the chief's house and search the desk with the open book on it. You should find a Power Seed.

Hint: Patrof: M-Water:
On the quest to find the Star Rune, go into the Tavern (located up and right from the Inn). Walk until you are in the top left area of the Tavern. Stand on the right side of the wood pile and search. The game will say that you found a bottle of M-Water at your feet.

Hint: Rabelesk: Potion:
In Rabelesk, walk up to the jars and search to find a potion.