Editing the handles from a point in a vector line/shape.
When editing the handles from a point in a vector line/shape, it usually takes high accuracy to select the handle. It can be very frustrating to try and grab a handle, and you end up grabbing the shape underneath it instead - and moving the shape instead of adjusting the handle. I guess the tolerance on how close the cursor needs to be to the handle, has something to do with this. Maybe putting in a different logic that will understand that if a point on a line is selected and it displays the handles - then it is highly likely that the users next step will be to grab and edit the handles.
I hope this made any sense :-)