I had a very difficut time in the central room at at Source Temple. Simply because the games doesn't give any hints or help at all that you'll need a rather high perception. I had to go to the Dark Room in my homestead and I had to redistribute all of my talents, abilites etc. to get a high percpetion of 14 or 15. And then I could go on. For some quests, like the Maradino quest, perception really is the key to finding the entrance to the Maradino's cave.
Little did I know that having my two main characters redistribute their talents, abilities and primary stats would also mean that the spells etc. they have learned during the game. I had to go to the elemental halls in the Homestead to get some of the spells back. I even find to Cyseal to get some other spells etc. Luckily I had some equipment, I could use in bartering. I didn't notice Molok saying anything about that the characters would loose all the memory of the spells they have learned
during the game.