This is a complex series. It's very interesting. The only thing I would worry about is violence because it can get violent sometimes, but most of the time there's just punching, kicking, etc.
What is CSM talking about!? They say that that they use always fighting to solve conflict? CSM, you gotta realize that the Shredder is trying kill the turtles, and I'm not saying that violence is good, but in a superhero show it will be used. And parents might wanna watch out for some of the violence in this show (like when Leo was stabbed). It's overall a good and complex series.