There was this, and a scene after the door to Erebor didn't open at sunset that Richard talked about, and both NEED to be shown.
The scene involving Thrain is pretty important to the story, and about Thorin's fears and doubts about himself, and just to see Thrain and Thorin during the battle of Azulnabar (I assume) would be amazing.
And the scene involving the door to Erebor, Richard said that it was really an all time low for Thorin, though I can't find the exact interview, but that scene was heart wrenching enough (the way Thorin can only say "That's what it says" just... ugh. emotion_0A0 ), but it felt somewhat oh, they gave up, Bilbo saves the day Thorin's back let's go SMAUG! It needed a little bit more to it.