When it comes to using adrenaline, there is really only so much you can use. The body doesn't have a controlled release of adrenaline. That's why its called a "dump." It dumps, and then it is done. Now, being able to control what startles you, and delay the dump, is a trainable thing. But not how much adrenaline your body uses at a time, I believe. As for Chinese/Japanese influences on TKD; yes, they are there. But, not everyone in the MAs are zen masters, and so it is with TKD. I don't worry about the internal so much.