Ra's al Ghul's first name is inconsistently pronounced in this movie. Sometimes it's pronounced "raish," (as it was pronounced in "Batman: The Animated Series") and other times it's "raz" (as in "Batman Begins").
It is never explained why Batman can use his cure for Scarecrows fear gas on the turtles. The fear gas was not made for animal DNA and the turtles outside of there mutation are still animals. Batman is never seen making a special serum for them, and yet he is able to use it on one of the turtles, curing him instantly. There is no explanation as to why he is able to do this and it is left oblivious.