I think the Turtles would learn how Sokka feels in the battles...
They're great warrior, but they would have to adjust to the new fighting styles they'll be going against.
Shredder and all TMNT villains would find themselves also fighting against the Fire Nation in this, as Shredder wants to be the boss, not follow others. and the Fire Nation won't back down. Over all, it would be a three way battle in which the TMNT would have to join forces with the Foot to go against the Fire Nation, than turn their battle towards the Foot once they're done.
i dont know.... i think shred-head and ozai would get along fine.
They could call the show
michelangelo the last pizza bender" 