Here's the thing: a "must do" is different for everyone.
Is it a "must-do" in the sense of "I've never been to Disney/haven't been in a while and want the Disney experience"? or is it "we're finally without the kid(s) and want a romantic getaway must-do?
As an adult family, I can tell you our must-dos:
- You're staying in AKL. I'd always recommend Boma, but for a couple looking for a romantic meal, I'd go with Jiko or Sanaa.
- I'd do Yachtsman. Book it for a later time. What I'd do is grab an ice cream from Beaches and Cream or Ample Hills after and watch Illuminations from either the bridge connecting the BW to BC area, or from the Yacht Club boat launch (or grab a seat on the Beach Club beach)
- We loved Homecomin'. Not exactly romantic, but a fantastic meal.
- California Grill - as romantic as it gets... but don't overlook Narcoossee's. Narcoossee's is a family favorite for us.
Bars:
DHS: Go to Tap House. Cool beers and vibe. Perfect for people watching and the pretzel is fantastic
Epcot: Drink around the world is the easy answer;
Disney Springs: Jock Lindseys has a cool theme; Enzo's Hideaway is better for mixed drinks, but cool nonetheless; Polite Pig has a cool bar and has outstanding food—Just bar hop and see what you like. There's so many great spots.
MK Area: Geyser Point at Wilderness Lodge is very relaxing; Trader Sam's at Poly.... maybe try a monorail crawl?
Edit: Oh yeah... one of my favorite nights ever was when my sister and I went to Raglan Road for late-night food and beers. There was a guy playing acoustic covers outside. It was so great.