Sci-Fi Dine In: Well, I have been told more often than not to avoid this one. I keep saying we will try it, but we always end up going back to 50's Prime Time Cafe! its great for lunch, this trip (in december!) we will do it for dinner.
Akershus Royal Banquet Hall: this is on our must make ADR for for breakfast. everyone in our party (from 2yr old dd to 'not saying how old' grandmother) wants to do this.
Liberty Tree Tavern, Character Dinner: i have heard good things about it! we for our trip have to choose between this or 1900 park fare, and we want 1900 park fare. (it will coordinate better wiht our park plans for the day too.) HOwever, when we go to MK we are going to do Crystal Palace. I don't think either place u can go wrong. (however Liberty Tree is family dining, and its turkey i think! yummmmm)
Cinderella's Gala Feast: imo its not worth the money but thats my opinion. since we are doing 1900 park fare dinner we will get the character princess experience, and no so we aren't eating in the castle, but for twice the price i didn't feel it was worth it to eat in the castle, but again just my opinion. i also have 2 kids who wouldn't know that they missed it. in a few years when we go back,(and they are older and wiser than me) we may have to add it in.
Spirit of Aloha Luau:this sounds like great fun!!! never did it, but sounds like fun!
All in all i think your choices are great. u can always read online the menus at each place to confirm your desire to eat there.
happy planning!
edited for errors.