🚀 go-pugleaf

A frequent function in vector tools is to draw a straight line and, while holding the mouse, drag the point to the desired position before dropping and fixing it. (unlike the dragging of the pen tool that modifies the handles of the point)
Freehand's bezigon tool did this quite well-

I know that in illustrator I can do the same holding the space bar and maintaining the mouse clicked, but, personally, i find it a cumbersome and slow key combination. Besides ,frequently I want to constraint the angles of the lines with shift or alt, requiring a really uncomfortable two or three fingers position that can't be customized.

I wouldn't want to add new tools to AI (actually i would remove some of them), but i could use this bezigon function in my daily work.
Another option would be assigning the pen tool an optional bezigon option that you can turn on and off. This behaviour would deactivate the dragging of the handles of the anchor point, moving the anchor point instead.

A third option would be to draw a preview of the next segment before fixing it (like the excellent Aviary's Raven does)