I would like to offer some insight and questions.
There is elastic physics between the balls, but only when the player is not supplying any input. This is to prevent the player from simply dragging the red ball to the goal and getting a 0 par. How would you prevent this if the red ball was always being pulled to the blue one?
I agree about the ball swinging while you are shooting being annoying and am looking into alternative ways of control to avoid that. If you don't try to hold your aim then it feels much better.
I personally think the mouse controls are fine (aside from the above concern). It does not matter where you begin to click, it is all relative. Click and drag to the left, blue ball attempts to move to the left of the red ball. The blue ball is essentially your cursor. How do you envision seeing the mouse cursor itself aiding?