Boma dinner is nice and we also did it on our AK day. But it is at the AK Lodge hotel, not at the theme park. It is a nice ending to a day at AK though! Most desserts had alcohol in them but my kids enjoyed the cookies very much (no alcohol of course!!). There were the usual children's selections on the dinner buffet too.
At Epcot we prefer to dine in the World Showcase since we enjoy experiencing cuisine of different cultures. We ate at Biergarten for dinner and loved it. It was a German buffet (excellent German food and some great choices for picky eaters) with a wonderful live band. Highly recommended! My kids loved the entertainment and again, great kids' selections at the buffet.
At DHS, I don't know about TS. I think I would go to either Beach Club, Yacht Club or Boardwalk and try a restaurant. One that comes to mind is Cape May Cafe at Beach Club which is a seafood and American buffet. We have not eaten there but plan to eat there on our next trip especially since we will be staying just across the lake at BWV. You could also try one of the signature places, either FLying Fish on the Boardwalk or Yachtsman's steakhouse at Yacht Club, both get rave reviews. The "regular" a la carte restaurants in that area are Spoodles at BW and Captain's Grille at Yacht Club. There is also ESPN Club on the Boardwalk but they do not take ADRs. Our DHS day we ate at 1900 Park Fare at Grand Floridian with Cinderella, Prince Charming and the stepmother and stepsisters. We liked it a lot! However if I HAD to choose a TS at DHS I would probably try 50s Prime Time. We may try it on our next trip but not too sure. It has a 50s theme and people seem to like the food there, and the servers are funny from what I hear and very good with kids. DHS also has a character breakfast and lunch at Hollywood & Vine. We went to the breakfast and it was wonderful with JoJo & Goliath and the Little Einsteins, although this is definitely better for really little kids like mine.
Good luck with whatever places you choose and enjoy!