>>4464
Domenico set himself on fire to be a martyr of sorts. To show how strong his faith was and in what he was preaching to humanity. Sacrificing himself in hopes that they'll see his undying conviction and to consider what he's told them.
I think the candle bit was Andrei (who said earlier that he understood Domenico) trying to show that he too could make a sacrifice (however small it was in scale) and putting faith in Domenico and his beliefs. Perhaps him going through with this one final test of patience and will had some great meaning or purpose to Andrei? I haven't figured this all out myself, tbh.
In the hot springs bit near the beginning they talk about Domenico, his faith and how a madman is very similar if not identical to a spiritual man. The ones in the hot springs are basically your average secular people. With no spirituality or faith in their lives, they believe only what they see and experience and act as if they're "realists". So when they see a man so devoted to his faith, they'll think he's unusual because he's not like them. So he's cast aside and labeled as a madman for his unusual beliefs and actions because they fail or maybe even refuse to see the world through his eyes.
Eugenia got fed up with Andrei's indifference towards her feelings. She wanted to be loved by him. He goes through the whole film not recognizing it or, maybe he does but will never do anything because his love for his wife and family is too great. I think it's the latter considering, Eugenia shows up in at least one of the dream scenes with Andrei's wife, I guess to make the point that Andrei perhaps sees them as similar if not the same person in this sort of confused and depressed state he's been in.
But anyways, she moves on and goes back to her boyfriend (who she brought up earlier in an attempt to make Andrei jealous but he didn't give a shit anyways) and it's obvious she's not happy with this boyfriend. He seemingly doesn't give a shit about her too.