Steph,
Thanks for breaking this question out separately from your itinerary question. There is just too much to say on each subject to fit in one answer!
Some of my dining favorites for adult groups are as follows, by location;
Magic Kingdom
Not a lot here geared to adult-only dining, so I prefer to leave the park and head to nearby resorts. See below for ideas from the Grand Floridian, Polynesian, Contemporary, and Wilderness Lodge.
Epcot
So many choices, so little time! Teppan Edo is good, but you should also think about Marrakesh, Biergarten, Les Chefs de France, and Tutto Italia.
Hollywood Studios
Hollywood Brown Derby, 50's Prime Time Cafe
Animal Kingdom
Yak & Yeti, Tusker House
Downtown Disney
Raglan Road, Bongos
BoardWalk
Flying Fish
Resorts
California Grill (Contemporary)
Jiko, Boma (Animal Kingdom Lodge)
Narcoossee's (Grand Floridian)
Whispering Canyon Cafe (Wilderness Lodge)
Kimonos and Il Mulino (Swan)
bluezoo (Dolphin)
There are a lot of other good choices, based on other cuisine and experience, so ask for something specific and I can recommend further. In particular I only listed table service here, but I can recommend some quick service too!
Have a magical (and delicious) vacation!