Using the pencil tool. I'm sorry, I'm not being clear. The nodes look smooth when they are laid down, and on the canvas they look smooth but when you examine them individually they behave as corner nodes.
The handles of the node are collinear, that's what makes the node smooth. If the handles do not rotate together in the node editor, that's a problem with the node editor which we must fix.
Ctrl A and making them all symmetric has a marked smoothing effect on the drawn curve. Have you looked at laying down the curve with symmetric nodes?
Surely making them symmetric adds smoothness. But I'm afraid that making them symmetric while drawing would make the line too distorted (i.e. too far from the line you drew) and "jerky" as you describe below. We might try, however.
Do you agree that the calligraphic tool has a much less "jerky" drawing action than the pencil tool?
If by "jerky" you mean that calligraphic is closer to the actual line you drew, then yes. But I think the purposes of the two tools are different. For calligraphic, I need exact reproduction of my movements, with all trembles and wiggles, because that makes calligraphy look natural. With freehand, I usually need to draw some abstract geometric shape, and here I need it to generalize and smooth my drawing, much as it does now. The problem seems to be that when people draw on too small a scale (like Bryce did) it generalizes out the essential elements of the line rather than the artifacts, and that gives the impression of jerkiness. I draw on a larger scale and faster, so for me this generalization works very well.