The Hero's Path

Why sell spells if you can unlock the secret and learn a bunch of spells (including raising the dead)? It seems like you also need to add unlocking the secret to the blacklist on this map.

It's simply a choice between fair options – spells are readily available and relatively inexpensive, so you can just buy them, or get the secret if you prefer. It doesn't affect anything. Raising the dead is also available for a small price if you choose to play as a dark mage-lich (the logic is – if you sympathize with necromancers, you get raising the dead). But forbidden skills specifically break a certain aspect of the game mechanics, which is different from the standard one in this map.