You should probably try to get Heat Wave on Charizard in place of Flame Burst, as it can manipulate the surroundings, which is always useful.
With the Zoroark, I suggest that you leave the movepool as is, as you already have a fire user in Charizard and Foul Play is useful in general.
I would suggest Shadow Ball for the Jolteon, but that TM is not available yet, so just sit tight until then.
Sylveon could probably replace its last two moves with Hyper Voice, which I believe is a move tutor move, and Echoed Voice, which is a TM you get much later in the story. Until then, keep Quick Attack. Priority is always useful.
Vaporeon could probably keep Quick Attack, as I don't think it learns any other good special moves, but you could replace it with a status move if you want.
And that's about all I can suggest for the moment. Hope you found these helpful.