Here are the tasks you can complete early:
Hatch & evolve the Chapter 2, Chapter 6 and Chapter 7 dragons - in this event that would be Argument to level 14, Fury to level 06 and Embarrassed to level 12
In Chapter 4 you start crafting a Funflower (decor) - keep it in the Craft Shop until Chapter 5 where it tells you to decorate with it
In Chapter 6 you start crafting a Happy Masks (decor) - keep it in the Craft Shop until Chapter 7 where it tells you to decorate with it
For any Chapter that tells you to complete a quest (for example Chapter 7 step one is complete the Inner Peace Quest) you can start it early (overnight works for me) and then hit complete when prompted
Chapter 9, Craft a Superb Story (material) you will need 2 of these but you can start the first one early so it's done by the time you get to this step
Chapter 10, you can plant your Firapples early and harvest them when prompted
In Chapter 10 you need to craft and decorate with an Emotional Clock (decor) this can be crafted early but don't place until prompted
During the whole event, you should be completing quests for parts. Here's the breakdown of how many you need and how many you'll get from going on quests for tasks:
#1 – Inner Peace Quest (Perfect Prologues) – 10 needed total – 04 from tasks (2.5 hours)
#2 – Outer Calm Quest (Favored Fables) – 9 needed total – 02 from tasks (3 hours)
Hope this helps. If you have any questions, let me know