You’ve got a great load of suggestions but I’m going to echo that you should definitely get the 2-day park hoppers over going to Universal Studios- Hollywood. If you had more time I would maybe say USH is worth it, but the drive is a bad/traffic congestion one plus if you love Disney, there’s SO much that’s unique to DL that you will absolutely not have time for in 1 day.
I love Fantasyland and dark rides so I would definitely start in Fantasyland, even if just me & the hubby. I’d probably make sure to ride all the rides my kids aren’t tall enough for (yet) that I love (Indiana Jones, California Screamin’). And I’d probably try to make it so I got a couple of rides in on each of those. Both of those have single rider so you can ride together with 1 FP and then any additional rides take advantage of the single rider line to save time. I’d also make sure to ride my husband’s two favorites that we always have to rider switch, Star Tours & Radiator Springs racers as many times we could. Carsland is an absolute must so whether or not do you do 1 or 2 days, DEFINITELY park hop.
I would snack my way through the day since DL and DCA both have so many good quick service/snacks and then get a big meal somewhere around 2-4ish where you can sit down and just relax to power through until park close. Blue Bayou is a great choice for this. Carthay Circle is also beautiful but not the same immersive theming as Blue Bayou at all. Being an adults only trip you may want to check out the Carthay Circle lounge for drinks/appetizers too. We also love the Cove Bar on the Pier for drinks & lobster nachos but you have to line up before they open to not wait forever. The line can get 2 hrs long and people will wait in it!
I’d also use the afternoon/midday to do the lolly-gagging things we don’t usually do with the kids (stop & watch some of the bands in the park while eating a churro, do Animation Academy a couple of times to draw a couple of different characters without having to worry if one of the kids will need to leave for an emergency bathroom break, sit down and people watch in the hub or wherever, etc).
Some of our favorite snacks throughout the parks are skewers at Bengal BBQ in Adventureland, Beignets & Mint Juleps at Mint Julep Bar in New Orleans Square, anything sweet from the Pooh Corner confectionery counter, Candy Palace on Main Street or Trolley Treats on Buena Vista street in DCA, churros from any cart, Corn Dogs from Stage Door Cafe in Frontierland OR Red Wagon on Main Street or Hot-Link Corn Dog from Corn Dog Castle in DCA. Plaza Inn fried chicken is also amazing and can be bought ala carte for 3.99/breast. SO much better than getting the meal for 17.99. The twists from Maurice’s Snack cart in Fantasy Faire are also a great snack. Turkey legs and corn on the cob from several different carts in both DL & DCA are huge and delicious as well. And of course, all the ice cream! Golden Horseshoe has the secret menu Ice cream nachos (huge and amazing), there’s Dole Whips of course at the Tiki Room and then our favorite ice cream is Ghiradelli’s on the Wharf at DCA. Also, bread bowls & bread pudding from the Pacific Wharf Cafe in DCA are both amazing. Annnd, if you just need a small, quick snack, the Bakery Tour hands out free samples of sourdough and right across the walkway Ghiradelli’s has chocolates they hand out. Those are a few of our favorites, but really there’s so much more that’s pretty good too. The only places I would avoid are the quick service in ToonTown and the pizza place in Tomorrowland. The Harbour Galley in Critter Country was also only so-so but not all bad. Everywhere else has decent food at worst. Everything I’ve mentioned above are all favorites we have to make tough decisions on when we are deciding what to eat.