I'm not sure this game benefits much from the candle mechanic. Both that and the sequence where the characters need to run discourage exploration, despite the game requiring exploration to continue. The battle system isn't very interesting either. Without indication of what the other skills would do, I found myself just using support and attack.
Regarding that riddle to open the chest, are either the players or the characters themselves supposed to understand it? I don't see much reason to expect either, and I was surprised when the characters mention "God" later on, since the opening didn't give the impression they would've learned anything about religious teachings. To solve it, I just kept trying options until it worked, since none of the pieces went together in any way that I could figure, including the words on the pedestals not relating to the ones in the hint.