Just finished show - am confused

I just finished the show and am really confused. I just want to clear some things up so I have a few questions for anyone who knows. Thank you in advance for any replies!

1. Who is meng shuyan ( was given post humous status in episode 40)?

2. Did Jin Yuan Bao actually have a crush on Changyu or did I just imagine that?

3. Why did chancellor Wei get executed but not Minister Li? They both tried to usurp the throne.

4. Did chancellor Wei hallucinate the last meal with his nephew? Or was that something that happened before Zheng left for lin an?

5. How did they manage to permanetly move back to lin an if they are prominent political figures?? Zheng is the regent meaning he has to be at the palace reguarly. Also how has Changyu not seen the training grounds in 5 years if shes basically the supervisor?

6. Was the fire that Chancellor Wei and his ex-fiancee experienced before or after the crown princess fire?>!​!<