1. The document discusses several factors that are important for maintaining healthy, long-lasting relationships, including working hard at the relationship, allowing for open communication and conflict, and focusing on positivity and appreciation of one's partner.
2. It emphasizes the importance of intimacy, where partners truly know each other by opening up and sharing both strengths and weaknesses, rather than just seeking validation.
3. Successfully dealing with conflict involves addressing specific issues or behaviors respectfully rather than attacking the other person, and keeping a ratio of at least five positive interactions for every negative one.