But the others in my opinions were extremely useful, Jump, Levitation, Slowfall, Blind and Sound can become spells you can learn but then maybe Detect Key, Detect Enchantment, Sanctuary, Intervention and Mark/Recall can be obtainable only with a scroll (you know, one time scroll, after you do the spell it is destroyed), this way people won't become super powered or make the game too easy by just going back to the nearest shrine etc. every time they run out of health potions.
What do you think?