Welcome! I've added you to the list!
So, I can 100% recommend the WoC dessert party! We've done it a few times and are planning on it for this trip again. The last time we did F! dining package was quite a few years ago, back when Blue Bayou gave out seat cushions...I actually think I still have our somewhere in the basement.
As for things to make sure you don't miss vs things you can skip, there are a few attractions that are basically the same, some that are definitely better in DL and some that are better at WDW.
Off the top of my head and in no particular order, although I will see if I can go through the parks logically counter clockwise.
Tomorrowland:
Astro Orbitor - better at WDW simply because it is on top of a building
Buzz - better at DL, the guns are not fixed to the car so easier to shoot.
Star Tours - basically the same ride inside, WDW wins out because of the entrance.
Space Mountain - MUST do, it is without a doubt better at DL.
Autopia - better at DL
Finding Nemo Subs - unless you are claustrophobic like me, don't skip this
Fantasyland:
Dumbo - same as WDW but with a worse queue
TeaCups - same as WDW but without the benefit of the covered area.
Peter Pan - Similar to WDW, 100% worse queue at DL but the ride itself I think DL has this one.
King Arthur Carrousel - what can I say, it'a a carousel but if you are VERY lucky and quick, you can grab Jingles.
It's a Small World - I debate which is better, TBH. I love the outside of this at DL but I am on the fence about adding the IP characters.
Do not miss the rest of Fantasyland, especially Mr. Toad!
ToonTown:
Well, just don't skip this at all!
Galaxy's Edge:
You are right, the attractions here are basically identical as at WDW although interestingly the rocks that make up the land are different on both coasts to better fit in with the natural landscape of FL and CA.
Critter Country:
Depends on if Splash is still open but if it is, ride it! Not as big a drop as WDW's one had but this might be your last chance before the refurb.
Winnie the Pooh - skippable but it is cute with a typically short line.
New Orleans Square:
Haunted Mansion - slight differences but because DL's has the Hatbox Ghost, don't skip it!
Pirates: 100% the better version! Longer, with scenes the WDW one does not have, and also this one has 2 drops instead of 1.
Frontierland:
Big Thunder - debates all around for which is the better version so don't miss it and make up your own mind!
Adventureland:
Indiana Jones - same basic ride vehicle as Dinosaur but I think much better theming. Long ride queue, even with a LL so be prepared.
Treehouse - Closed for big refurb
Jungle Cruise - WDW takes this one without a doubt! Longer and with scenes that DL does not have.
I think that is all for DL., DCA will be much easier!
The only three rides I can think of off the top of my head that are similar are Little Mermaid, Toy Story Midway Mania, and Soarin'. Keep in mind, if Soarin' happens to be showing the original Soarin' over California, DO NOT SKIP IT!
Other than that, Guardians of the Galaxy: Mission Breakout is the same ride vehicle as ToT, but don't skip this, the music and theming is just great!
Phew, that was a short novel but hope it helps!