I agree with quakercub about Boma for breakfast. It’s an awesome buffet.
Also Crystal Palace for character breakfast at MK, although 8 yr old boys sometimes think the Pooh characters are too childish.
For sit-down you can’t go wrong with LeCellier at Epcot. I think even a picky eater would like the food there.
For fun, Whispering Canyon at WL is good, better if your child is not terribly shy as the servers sometimes interact with the guests and very sensitive children might not like that!
Most kids really LOVE Sci-Fi at MGM. It can be a bit pricey, but you can’t beat the atmosphere (milkshakes are awesome too!)
We like Tony’s at MK for soup, pizza and sandwiches, but not so much for the spaghetti. (DH makes much better sauce!)
I could go on and on. Most of all the restaurants on property are great.
And hey, if you are still lost, just let me know and I’ll be happy to be a tour guide!!!