There are almost no entrees or desserts excluded on the dining plan. The only entree that I've heard that is excluded is the prix fixe at Flying Fish. The feasts at Marrakesh can be ordered, but there's an additional charge of $5 or $7. Lobster (e.g. at Narcoossee's) is included. If you are interested in sushi, ask at the restaurant because that is one item that varies. Sometimes it can be ordered as an entree. The only dessert that is excluded is the Kitchen Sink at Beaches n Cream.
Items that are "for 2" usually require 2 people's credits.
The non-alcoholic beverage is usually a fountain drink (soda, coffee, tea, lemonade). However, the Disney owned restaurants are more liberal in their interpretation of the drink that's included. At some TS places we've also been able to order milk shakes, smoothies (no refills), pressed pot coffee and virgin cocktails - if you see something that interests you, ask your server. Not included are drinks in souvie glasses, specialty non-alc beverages, bottled sparkling water, many specialty coffees and teas.