I really liked the short, though I grew up watching Goof Troop, so seeing Pete cast as such a clear villain always jars me a bit, even though that's been his primary character function through most of his history (Mickey's Christmas Carol was especially creepy for that same reason).
The movie was terrific, with the exception that the music still hasn't recaptured the glory of the 1990s -- Hercules, Mulan, The Hunchback of Notre Dame and Pocahontas all have superb soundtracks, even though you can argue that this or Tangled have better storytelling/characterization. The new wave of 00s animated musicals generally manages one or two really strong songs (your "Friends on the Other Side" or "I See The Light"), the rest being functional (there's also the troll song, which I would have cut). Here, "Let It Go" is head and shoulders above everything else, and will probably make Robert Lopez an EGOT winner.
Idina Menzel's presence makes it hard not to think of Wicked throughout. Also, I don't get why you would cast Jonathan Groff and not give him any real songs.
Also I hope they exterminated those trolls afterward, because seriously, everything bad that happened in this movie was the result of their stupid advice.