If I do recall correctly, there's a fan team called Soapy Waffles. They plan on animating some/all of the unfinished episodes (Mopiness of Doom, Top of the Line, etc). Though it may take awhile, Mopiness of Doom is still unfinished as far as I know.
I'd give Applejack the boot for a couple episodes to have Derpy. No, I don't hate Applejack, but I think we've just about explored her entire character by this time. Her story is either over or hasn't started. She or Twilight would probably be the best. (Twilight because her arc is over)