Here! Most definitely here, gotta make a post soon, NaNo started so I got a bit distracted, but I'll make a post for SA soon.
The only thing I can think of, aside from making the group come together I think it would be a good idea to figure out how they would obtain the elements. Maybe you already have that planned of course.
Going by the first two episodes of MLP the individual ponies showed some of their traits already on their way to finding the elements of Harmony, and once they arrived, their full potential came to a bloom.
For a first situation I'd say maybe have 1 badguy they'd have to face off against, maybe as said a threat that destroys creativity(sounds more like a boss battle for later on once they're more a team and know what to do with their elements), or something that is simply a threat, but can be solved with creativity. Like the Sirens in the last movie, or Nightmare Moon in the first two episodes.
Once they've gotten the elements, I'd say just kind of let things flow, have them go on adventures, and build up to a boss battle at the end of the 'season'.
Hope that made sense