Just found your PTR & joining in! I had
kind of the same experience planning our most recent trip, except that I wasn't planning while pregnant, it was only once DS was born that we started to plan. However, they change SO MUCH month to month that I had no clue what he would be able to do, what his schedule would be, what his temperament would be, etc. by the time our trip rolled around! My best advice for this would be plan the trip you want, and change accordingly as you learn your baby. For example, DS has always been a weird sleeper. He would sleep fine in his pack & play, then his crib, at night, but for naps, he couldn't be put down! He would wake up within 10 minutes, so I spent several months on the rocker in his room with my Nook holding him while he slept for a couple of hours. It was madness, and eventually he grew out of it. But I was worried about him being able to nap in the stroller. So we took practice outings to the Zoo, the Aquarium, the park, etc and discovered he would in fact nap in his stroller, and that if there was a lot going on for him to look at, he could even skip or postpone his nap and not be a beast like he would be at home!!
As for the restaurants, we also took lots of practice outings to go eat. We discovered that he does well for a little while, but generally is hard to entertain for a meal, especially a long one. So we decided to cut back on our trip and only planned one sit-down lunch, and 2 character breakfasts. On the actual trip, he did great for the character breakfasts for the most part because there was always something happening, although he would start getting restless towards the end. Our lunch at Sci-Fi was just not worth it. He was going crazy the whole time! So I think it will be awhile before we plan anymore lunch or dinner sit-downs in Disney World. However, I'm telling you MY experience with MY child. Your little girl will have her own personality and she may do GREAT for sit-downs! After all this rambling, my point is just that you can really have no expectations for your trip & have to be able to change at the last minute as you learn your baby's personality and tolerances.
And to help with loud events (fireworks especially!), we got these:
Peltor Baby Earmuffs. We put them on DS one night when we went to the parks and decided to try to stay for Wishes. He fell asleep well before the fireworks, so we slipped the earmuffs on him and he mostly slept. Stirred a little towards the end, but nothing major. They really helped!
Sorry for rambling! We just learned SO MUCH taking DS on his first Disney trip! I'm doing a TR, so if you'd like to follow along, you might find some tips you never would have thought of for traveling with a baby! I read tons of TR's of people taking their babies to prepare for our trip & learned a LOT!