So Mike released the final part of his trio of blog entries on writing the episode "Beginnings" today. I don't know how much news it will have relative to the last 2 parts, but so far, there is at least enough to post this.
The airtime for Books 3 & 4 was decreased by a minute.
You can see that there were a lot of bits of dialogue cut in the final script. If you were following along with these posts, they were cut in similar places as the things cut in the Premise & the Outline. So the Bhanti Sage's part got cut a LOT. A semi-notable tidbit is that the draft has her using herbal medicine, indicating that Firebending can only read Chi, not heal.
Obviously, I will update if anything comes to light in the comments.
The Post, "Writing the Script": http://mikedimartinostory.com/2014/06/16/writing-the-script/#respond
Blog for Part 2, "Writing the Outline": http://avatar.wikia.com/wiki/User_blog:Neo_Bahamut/Beginnings_News_2:_Lion_Turtles,_Reincarnation,_%26_More!
Blog for Part 1, "Writing the Premise": http://avatar.wikia.com/wiki/User_blog:Neo_Bahamut/Beginnings_News:_The_Bhanti