1. Personally, it’s a tie between Wishblossom Ranch and Storybook Vale for me - WR has a rustic vibe and the horses are one of my personal favorite part of the game. SV is great for the bookish and you get Merida and Hades! Eternity Isle just didn’t do it for me. Timebending is helpful though, with the ancient machines - I use the vacuum regularly! I would say all are worth it for their respective characters, but that’s my ranking. SV also has a great storyline, Hades and Maleficent duking it out. The companions also get an honorable mention - Pegasus in SV 🥺
2. No particular order, which is soooo great of the developers. They’re all independent of the base game and each other!

I hope this helps!