i second the microwave macaroni...we get the Annie's brand (so at least it is somewhat healthy). we also buy canned fruit and canned green beans (which we'll eat room temp.) and baby carrots. that's 1 meal option that we'll use as a "break" from the restaurants or if we want something quick before heading back into the park.
breakfast food for us is often pbj sandwiches and juice boxes, but we also do granola bars, bagels and cream cheese, and dried cereal. all of this stuff can be found organic/no preservatives/no processed sugar, etc, so i feel good about starting our day with that (good thing, because Lord knows that once we are in the parks, anything goes for food with us!!) . we drive, so i always pack this stuff. not sure if publix has a decent natural food section.
your list looks pretty similar to mine. the only other thing i pack is "healthy" snack food...fruit leather, whole wheat crackers, raisins etc. not that we eat super healthy at home (and as i said, we eat loads of yummy junky stuff in the parks), but i know that my kids' behavior is better if they have some decent food at least for part of the day, especially first thing in the morning.
have you considering renting a fridge for your stay? if you are looking to save some money, even renting for part of your week might vary your food options quite a bit with the tiny freezer section and more space for cold items than a cooler. i don't know about your little one, but at 3 y.o., my kids still NEEDED milk. it would have been worth the cost to know that we didn't have to keep running out to get milk (and milk is EXPENSIVE in those little shops at the resorts!)
have fun!
. If you think it's a little too rich, water it down a little. You'll never notice over cereal. 
