Hooked again on Dean?

Now that Sal has spent a year away from Dean, he seems more enamored with him than ever. The first few chapters of Part II brought me to realize, however, that as an audience we do not know much about the character of Dean. As readers, we know only what Sal has told us, and Sal cannot help but see Dean in a nearly-divine light. For this reason, I see Sal as an unreliable narrator (thank you, AP lit vocab words). When I separate Dean from the compliments and obsession, he ceases to be the admirable character I envisioned.
While we were following Sal's adventure with his Mexican family, Dean was living a completely different life. He managed to get a job at a railroad that paid well, and began to settle down in a family, but then blew all the family cash on a car on a whim. He abandoned his daughter, Amy Moriarty, and her mother Camille without a second glance. "Without a qualm" (p. 103), he left Galatea Dunkel at a motel when she went broke. Then he begged Marylou on his knees to take him back, and nearly exploded his engine on the road. Is this really the kind of man Sal should be emulating? Even this new, 'mature' Dean seems highly self-centered and irresponsible. Sal admires his free spirit, but at this point in the novel Dean is looking more and more like an immature fool than a misunderstood genius.