EH008,
1) thanks for pointing out the discrepancy : I changed both initial & default settings to 30/45.
The idea there is not to propose the best setting (which would be 0 or 5 if your controller is perfectly calibrated), but to give a default setting avoiding issues with poorly-calibrated controllers, so newcomers can play the game with as few headaches as possible.

2) The Aiming Zone is noticeably bigger in TE4 compared to TE2013, and it was a goal of TE4 to avoid painting the lines too often, as it's more realistic like that. You could switch to Arcade controls which boost the Precision (but also lower the ball difficulty), making the controls close enough to TE2013's ones.