RE: clunking noise
I'm not sure about the clunking, sounds like one of those things I'd have to see.
There's a setting in the Castle Link that defines how fast the ESC response to throttle stick movement. Bring it down a few clicks. I dont have CL installed on this laptop or I'd tell you exactly what it was. I had the same thing with my Husky, move the throttle stick too fast and it would squeal and stop the prop till I brought it back down to idle. Clint from Castle straightened it out for me with one phone call.