Yes, you're correct there. I made a lot of assumptions to simplify the problem. It's like a bendy shaft on a golf club that effectively whips the head. I tried to address the snap in a way in the second point, but yeah, good point about the hand speed.
The disc has to rotate around your last point of contact just like the tip of a bullwhip.
I was trying to focus on the "heavy" sensation that the OP mentioned when ripping a disc, but you're absolutely correct, thanks for pointing it out!
Thanks for your answers and time again. I'm afraid that I'm too stupid to understand even the simplified versions you provided. Plus not being a native english speaker wont help that at all . Could not guess it would be that complex. At least now I remember why I lost interest in physics pretty quickly at school .